WO2019030033A1

WO2019030033A1 - Communication apparatus, method and computer program

Info

Publication number: WO2019030033A1
Application number: PCT/EP2018/070548
Authority: WO
Inventors: Muneender Chiranji; Srinivasan Selvaganapathy
Original assignee: Nokia Technologies Oy
Current assignee: Nokia Technologies Oy
Priority date: 2017-08-11
Filing date: 2018-07-30
Publication date: 2019-02-14
Anticipated expiration: 2020-02-11

Abstract

A method for transmitting from a communication device to a base station: part of the preamble in a special subframe for transitioning between an uplink mode and a downlink mode of communication, and another part of the preamble in an assigned uplink slot that is adjacent to the special subframe.

Description

Communication apparatus, method and computer program

Field

[0001] This disclosure relates to a communication, apparatus, method and computer program. Background [0002] A communication system may be a facility that enables communication between two or more nodes or devices, such as fixed or mobile communication devices. Signals can be carried on wired or wireless carriers.

[0003] An example of a cellular communication system is an architecture that is being standardized by the 3^rd Generation Partnership Project (3GPP). One development in this field is often referred to as the long-term evolution (LTE) of the Universal Mobile Telecommunications System (UMTS) radio- access technology. E-UT A (evolved UMTS Terrestrial Radio Access) is the air interface of 3GPP's Long Term Evolution (LTE) upgrade path for mobile networks. In LTE, base stations or access points (APs), which are referred to as enhanced Node AP (eNBs), provide wireless access within a coverage area or cell. In LTE, mobile devices, user devices or mobile stations are referred to as user equipment (UEs). Currently 3GPP is also developing the new 5G standards, known as New Radio. Such development is taking place, for example, in the Radio Access Network (RAN) working group.

[0004] Narrowband internet of things (NB-loT) is a technology which allows for low data rate communication between objects. The subcarriers and physical time structure used in NB-loT are similar to those used by LTE and, therefore, these two methods of communication can be combined. The combined system can benefit from orthogonality, if LTE and NB-loT are aligned in the frequency domain and time domain, and hence interference between NB-loT and LTE can be kept reasonably low without filtering. In certain circumstances, however, maintaining an alignment in the time domain between LTE and NB-loT communications can be a challenge. Summary of the Invention

[0005] According to a first aspect, there is provided a method comprising: transmitting a first part of an uplink channel in a first subframe that is configured for switching between a downlink mode and an uplink mode; and transmitting a second part of the uplink channel in at least one subframe immediately adjacent to the first subframe.

[0006] In one embodiment, the first part of the uplink channel comprises at least 3 symbols.

[0007] In one embodiment, the method comprises transmitting part of a further uplink channel in the first subframe.

[0008] In one embodiment, the further uplink channel is a physical uplink shared channel. [0009] In one embodiment, the transmissions of the first part of the uplink channel and the second part of the uplink channel are made according to narrow band internet of things.

[0010] In one embodiment, the first part of the uplink channel and the second part of the uplink channel comprise at least part of a physical random access channel preamble.

[0011] In one embodiment, the physical random access channel preamble comprises a cyclic prefix.

[0012] In one embodiment, the transmissions of the first part of the uplink channel and the second part of the uplink channel are made according to time division duplex.

[0013] In one embodiment, the first subframe comprises an Uplink Pilot Time Slot comprising the first part of the uplink channel.

[0014] In one embodiment, the transmissions of the first part of the uplink channel and the second part of the uplink channel are made in one of: in band mode of operation or guardband mode of operation.

[0015] In one embodiment, the method comprises dynamically adjusting the configuration of subframes that are configured for switching between a downlink mode and an uplink mode.

[0016] In one embodiment, the method comprises: transmitting the subframes that are configured for switching between a downlink mode and an uplink mode in a first configuration when each of the subframes comprise a part of an uplink channel; and transmitting the subframes that are configured for switching between a downlink mode and an uplink mode in a second configuration when the subframes do not comprise a part of an uplink channel.

[0017] In one embodiment, the first configuration comprises a greater number of symbols reserved for uplink transmission than the second configuration.

[0018] In one embodiment, the transmissions of the first part of the uplink channel and the second part of the uplink channel comprise transmissions according to a second protocol, the method further comprising: transmitting and receiving data according to a first protocol, wherein the data transmitted according to the first protocol is aligned in time with the transmissions according to the second protocol.

[0019] In one embodiment, the data transmitted and received according to the first protocol comprises a second subframe that is configured for switching between a downlink mode and an uplink mode, wherein the difference in time between an end of the downlink received data in the second subframe and the start of the uplink transmission in the first subframe is at least one symbol.

[0020] According to a second aspect, there is provided a method comprising: receiving a first part of an uplink channel in a first subframe that is configured for switching between a downlink mode and an uplink mode; and receiving a second part of the uplink channel in at least one subframe immediately adjacent to the first subframe. [0021] In one embodiment, the first part of the uplink channel comprises at least 3 symbols.

[0022] In one embodiment, the method comprises receiving part of a further uplink channel in the first subframe.

[0023] In one embodiment, the further uplink channel is a physical uplink shared channel.

[0024] In one embodiment, the first part of the uplink channel and the second part of the uplink channel are according to the narrow band internet of things protocol.

[0025] In one embodiment, the first part of the uplink channel and the second part of the uplink channel comprise at least part of a physical random access channel preamble.

[0026] In one embodiment, the physical random access channel preamble comprises a cyclic prefix.

[0027] In one embodiment, the first part of the uplink channel and the second part of the uplink channel are made according to time division duplex.

[0028] In one embodiment, the first subframe comprises an Uplink Pilot Time Slot comprising the first part of the uplink channel.

[0029] In one embodiment, the first part of the uplink channel and the second part of the uplink channel are in one of: in band mode of operation or guardband mode of operation.

[0030] In one embodiment, the method comprises receiving dynamically adjusted subframe configurations of subframes that are configured for switching between a downlink mode and an uplink mode.

[0031] In one embodiment, the method comprises: receiving the subframes that are configured for switching between a downlink mode and an uplink mode in a first configuration when each of the subframes comprise a part of an uplink channel; and receiving the subframes that are configured for switching between a downlink mode and an uplink mode in a second configuration when the subframes do not comprise a part of an uplink channel.

[0032] In one embodiment, the first configuration comprises a greater number of symbols reserved for uplink transmission than the second configuration.

[0033] In one embodiment, the first part of the uplink channel and the second part of the uplink channel are according to a second protocol, the method comprising: transmitting and receiving data according to a first protocol, wherein the data received according to the first protocol is aligned in time with the data received according to the second protocol.

[0034] In one embodiment, the data transmitted and received according to the first protocol comprises a second subframe that is configured for switching between a downlink mode and an uplink mode, wherein the difference in time between an end of the downlink transmission in the second subframe and the start of the uplink reception in the first subframe is at least one symbol. [0035] According to a third aspect, there is provided a computer program comprising instructions such that when the computer program is executed on a computing device provides a method, the computing device is arranged to perform the steps of any of the first and second aspect.

[0036] According to a fourth aspect, there is provided an apparatus comprising: at least one processor and at least one memory including computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to: transmit a first part of an uplink channel in a first subframe that is configured for switching between a downlink mode and an uplink mode; and transmit a second part of the uplink channel in at least one subframe immediately adjacent to the first subframe.

[0037] In one embodiment, the first part of the uplink channel comprises at least 3 symbols.

[0038] In one embodiment, the apparatus is configured to: transmit part of a further uplink channel in the first subframe.

[0039] In one embodiment, the further uplink channel is a physical uplink shared channel.

[0040] In one embodiment, the transmissions of the first part of the uplink channel and the second part of the uplink channel are made according to narrow band internet of things.

[0041] In one embodiment, the first part of the uplink channel and the second part of the uplink channel comprise at least part of a physical random access channel preamble.

[0042] In one embodiment, the physical random access channel preamble comprises a cyclic prefix.

[0043] In one embodiment, the transmissions of the first part of the uplink channel and the second part of the uplink channel are made according to time division duplex.

[0044] In one embodiment, the first subframe comprises an Uplink Pilot Time Slot comprising the first part of the uplink channel.

[0045] In one embodiment, the transmissions of the first part of the uplink channel and the second part of the uplink channel are made in one of: in band mode of operation or guardband mode of operation.

[0046] In one embodiment, the apparatus is configured to dynamically adjust the configuration of subframes that are configured for switching between a downlink mode and an uplink mode.

[0047] In one embodiment, the apparatus is configured to: transmit the subframes that are configured for switching between a downlink mode and an uplink mode in a first configuration when each of the subframes comprise a part of an uplink channel; and transmit the subframes that are configured for switching between a downlink mode and an uplink mode in a second configuration when the subframes do not comprise a part of an uplink channel.

[0048] In one embodiment, the first configuration comprises a greater number of symbols reserved for uplink transmission than the second configuration. [0049] In one embodiment, the transmissions of the first part of the uplink channel and the second part of the uplink channel comprise transmissions according to a second protocol, the apparats being configured to: transmit and receive data according to a first protocol, wherein the data transmitted according to the first protocol is aligned in time with the transmissions according to the second protocol.

[0050] In one embodiment, the data transmitted and received according to the first protocol comprises a second subframe that is configured for switching between a downlink mode and an uplink mode, wherein the difference in time between an end of the downlink received data in the second subframe and the start of the uplink transmission in the first subframe is at least one symbol.

[0051] According to a fifth aspect, there is provided an apparatus comprising: at least one processor and at least one memory including computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to: receive a first part of an uplink channel in a first subframe that is configured for switching between a downlink mode and an uplink mode; and receive a second part of the uplink channel in at least one subframe immediately adjacent to the first subframe.

[0052] In one embodiment, the first part of the uplink channel comprises at least 3 symbols.

[0053] In one embodiment, the apparatus is configured to receive part of a further uplink channel in the first subframe.

[0054] In one embodiment, the further uplink channel is a physical uplink shared channel.

[0055] In one embodiment, the first part of the uplink channel and the second part of the uplink channel are according to the narrow band internet of things protocol.

[0056] In one embodiment, the first part of the uplink channel and the second part of the uplink channel comprise at least part of a physical random access channel preamble.

[0057] In one embodiment, the physical random access channel preamble comprises a cyclic prefix.

[0058] In one embodiment, the first part of the uplink channel and the second part of the uplink channel are made according to time division duplex.

[0059] In one embodiment, the first subframe comprises an Uplink Pilot Time Slot comprising the first part of the uplink channel.

[0060] In one embodiment, the first part of the uplink channel and the second part of the uplink channel are in one of: in band mode of operation or guardband mode of operation.

[0061] In one embodiment, the apparatus is configured to receive dynamically adjusted subframe configurations of subframes that are configured for switching between a downlink mode and an uplink mode. [0062] In one embodiment, the apparatus is configured to: receive the subframes that are configured for switching between a downlink mode and an uplink mode in a first configuration when each of the subframes comprise a part of an uplink channel; and receive the subframes that are configured for switching between a downlink mode and an uplink mode in a second configuration when the subframes do not comprise a part of an uplink channel.

[0063] In one embodiment, the first configuration comprises a greater number of symbols reserved for uplink transmission than the second configuration.

[0064] In one embodiment, the first part of the uplink channel and the second part of the uplink channel are according to a second protocol, the apparatus is configured to: transmit and receive data according to a first protocol, wherein the data received according to the first protocol is aligned in time with the data received according to the second protocol.

[0065] In one embodiment, the data transmitted and received according to the first protocol comprises a second subframe that is configured for switching between a downlink mode and an uplink mode, wherein the difference in time between an end of the downlink transmission in the second subframe and the start of the uplink reception in the first subframe is at least one symbol.

[0066] According to a sixth aspect, there is provided an apparatus comprising: means for transmitting a first part of an uplink channel in a first subframe that is configured for switching between a downlink mode and an uplink mode; and means for transmitting a second part of the uplink channel in at least one subframe immediately adjacent to the first subframe.

[0067] According to a seventh aspect, there is provided an apparatus comprising: means for:

receiving a first part of an uplink channel in a first subframe that is configured for switching between a downlink mode and an uplink mode; and means for receiving a second part of the uplink channel in at least one subframe immediately adjacent to the first subframe. Brief Description of Figures

[0068] Some examples will now be described in further detail, by way of example only, with reference to the following examples and accompanying drawings, in which:

[0069] Figure 1 shows a schematic example of a wireless communication system where some examples may be implemented;

[0070] Figure 2 shows an example of a communication device;

[0071] Figure 3 show an example of an LTE carrier and NB-loT carriers;

[0072] Figure 4 shows an example of different UL/DL configurations that may be applied for an LTE frame when using time division duplex (TDD);

[0073] Figure 5 shows an example of a symbol group that is part of P ACH preamble; [0074] Figure 6 shows examples of different symbol groups that are part of a P ACH preamble;

[0075] Figure 7 shows an example of a symbol group that is part of a PRACH preamble;

[0076] Figure 8 shows an example of a symbol group that is part of a PRACH preamble;

[0077] Figure 9 shows an example of subframes that may be used to switch between downlink and uplink transmission mode;

[0078] Figure 10 shows an example of different subframes that may be transmitted by a communication device over a period of time;

[0079] Figure 11 shows an example method that may be performed in a communication device;

[0080] Figure 12 shows an example method that may be performed in a base station;

[0081] Figure 13 shows an example control apparatus; and

[0082] Figure 14 shows an example of a non-transitory computer readable medium.

Detailed Description

[0083] Before explaining in detail the examples, certain general principles of a wireless communication system and mobile communication devices are briefly explained with reference to Figures 1 to 2 to assist in understanding the technology underlying the described examples.

[0084] In a wireless communication system 100, such as that shown in figure 1, mobile communication devices or user equipment (UE) 102, 104, 105 are provided wireless access via at least one base station or similar wireless transmitting and/or receiving node or point. A base station is referred to as an eNodeB (eNB) in LTE. Base stations are typically controlled by at least one appropriate controller apparatus, so as to enable operation thereof and management of mobile communication devices in communication with the base stations. The controller apparatus may be located in a radio access network (e.g. wireless communication system 100) or in a core network (CN) (not shown) and may be implemented as one central apparatus or its functionality may be distributed over several apparatus. The controller apparatus may be part of the base station and/or provided by a separate entity such as a Radio Network Controller (RNC). In Figure 1 control apparatus 108 and 109 are shown to control the respective macro level base stations 106 and 107. In some systems, the control apparatus may additionally or alternatively be provided in a radio network controller.

[0085] LTE systems may, however, be considered to have a so-called "flat" architecture, without the provision of RNCs; rather the eNB is in communication with a system architecture evolution gateway (SAE-GW) and a mobility management entity (MME), which entities may also be pooled meaning that a plurality of these nodes may serve a plurality (set) of eNBs. Each UE is served by only one MME and/or S-GW (serving gateway) at a time and the (e) NB keeps track of current association. SAE-GW is a "high-level" user plane core network element in LTE, which may consist of the S-GW and the P-GW (packet data network gateway). The functionalities of the S-GW and P-GW are separated and they are not required to be co-located.

[0086] In Figure 1 base stations 106 and 107 are shown as connected to a wider communications network 113 via gateway 112. A further gateway function may be provided to connect to another network.

[0087] The smaller base stations 116, 118 and 120 may also be connected to the network 113, for example by a separate gateway function and/or via the controllers of the macro level stations. The base stations 116, 118 and 120 may be pico or femto level base stations or the like. In the example, stations 116 and 118 are connected via a gateway 111 whilst station 120 connects via the controller apparatus 108. In some examples, the smaller stations may not be provided.

[0088] The devices 102, 104, 105, described above may also be configured to send and receive communications in accordance with Narrowband Internet of Things (NB-loT) in addition to sending and receiving LTE communications. The devices may be UE devices and may exchange NB-loT communications with base stations 116, 118, and 120 or may exchange NB-loT communications with other UE devices.

[0089] A user device (user terminal, user equipment (UE) or mobile station) may refer to a portable computing device that includes wireless mobile communication devices operating with or without a subscriber identification module (SIM), including, but not limited to, the following types of devices: a mobile station (MS), a mobile phone, a cell phone, a smartphone, a personal digital assistant (PDA), a handset, a device using a wireless modem (alarm or measurement device, etc.), a laptop and/or touch screen computer, a tablet, a phablet, a game console, a notebook, and a multimedia device, as examples. It should be appreciated that a user device may also be a nearly exclusive uplink only device, of which an example is a camera or video camera loading images or video clips to a network.

[0090] By way of illustrative example, the various example implementations or techniques described herein may be applied to various user devices, such as machine type communication (MTC) user devices, enhanced machine type communication (eMTC) user devices, Internet of Things (loT) user devices, and/or narrowband loT user devices.

[0091] loT may refer to an ever-growing group of objects that may have Internet or network connectivity, so that these objects may send information to and receive information from other network devices. For example, many sensor type applications or devices may monitor a physical condition or a status, and may send a report to a server or other network device, e.g., when an event occurs. Machine Type Communications (MTC, or Machine to Machine communications) may, for example, be characterized by fully automatic data generation, exchange, processing and actuation among intelligent machines, with or without intervention of humans. [0092] In an example implementation, a user device or UE may be a UE/user device with ultra-reliable low latency communications (U LLC) applications. A cell (or cells) may include a number of user devices connected to the cell, including user devices of different types or different categories, e.g., including the categories of MTC, NB-loT, URLLC, or other UE category.

[0093] In LTE (as an example), core network 150 may be referred to as Evolved Packet Core (EPC), which may include a mobility management entity (MME) which may handle or assist with mobility/handover of user devices between BSs, one or more gateways that may forward data and control signals between the BSs and packet data networks or the Internet, and other control functions or blocks.

[0094] A possible UE will now be described in more detail with reference to Figure 2 showing a schematic, partially sectioned view of a UE 200. An appropriate UE may be provided by any device capable of sending and receiving radio signals. Non-limiting examples comprise a mobile station (MS) or mobile device such as a mobile phone or what is known as a 'smart phone', a computer provided with a wireless interface card or other wireless interface facility (e.g., USB dongle), personal data assistant (PDA) or a tablet provided with wireless communication capabilities, or any combinations of these or the like. A UE may provide, for example, communication of data for carrying communications such as voice, electronic mail (email), text message, multimedia, and so on. Users may thus be offered and provided numerous services via their communication devices. Non-limiting examples of these services comprise two-way or multi-way calls, data communication or multimedia services or simply an access to a data communications network system, such as the Internet. Users may also be provided broadcast or multicast data. Non-limiting examples of the content comprise downloads, television and radio programs, videos, advertisements, various alerts and other information.

[0095] The UE 200 may receive signals over an air or radio interface 207 via appropriate apparatus for receiving and may transmit signals via appropriate apparatus for transmitting radio signals. In Figure 2, transceiver apparatus is designated schematically by block 206. The transceiver apparatus 206 may be provided for example by means of a radio part and associated antenna arrangement. The antenna arrangement may be arranged internally or externally to the mobile device.

[0096] A UE is typically provided with at least one data processing entity 201, at least one random access memory 202, at least on read only memory 209, and other possible components 203 for use in software and hardware aided execution of tasks it is designed to perform, including control of access to and communications with access systems and other communication devices. The at least one random access memory 202, and the at least one read only memory 209 may be in communication with the data processing entity 201, which may be a data processor. The data processing, storage and other relevant control apparatus can be provided on an appropriate circuit board and/or in chipsets. This feature is denoted by reference 204. The user may control the operation of the mobile device by means of a suitable user interface such as key pad 205, voice commands, touch sensitive screen or pad, combinations thereof or the like. A display 208, a speaker and a microphone can be also provided. Furthermore, a UE may comprise appropriate connectors (either wired or wireless) to other devices and/or for connecting external accessories, for example hands-free equipment, thereto.

[0097] It would be understood by the person skilled in the art that a UE may not include all of the features discussed above with respect to figure 2, but may be simpler than the example presented. A UE need not include, for example, a display 208 or a speaker. It should be appreciated that in some examples, a device with communications ability may be used.

[0098] As explained earlier, certain methods of communication, such as LTE and NB-loT may be combined and transmitted together. There are 3 modes of operation that may be used for NB-loT in combination with LTE. Reference is made to figure 3, which illustrates examples of each of these 3 possible modes.

[0099] Figure 3 shows an LTE carrier signal 310. The carrier signal has a bandwidth of 10 MHz. Thus, it is possible for an LTE operator to deploy NB-loT carrier signals within an LTE carrier by allocating one of the physical resource blocks (PRB), which also have a width of 180 KHz, to an N B-loT carrier. This mode of operation is referred at as an in-band operation, and is illustrated in figure 3, by the NB-loT in-band carrier signal 320.

[0100] Instead of allocating one of the PRBs of the LTE carrier for NB-loT, an NB-loT signal 330 may be implemented in the guardband at the side of the LTE signal. The guardband is a part of the spectrum at the edge of an LTE carrier signal that is not formally allocated for use by the LTE system. The guardband exists to prevent interference between the LTE carrier signal and any adjacent signal, e.g. a further LTE carrier signal.

[0101] A third option for implementing NB-loT is standalone deployment. Unlike inband or guardband operation, standalone deployment utilizes bandwidth that is not reserved by the existing LTE network. As shown in figure 3, a standalone NB-loT signal 340 may be located in an unused part of the spectrum away from the LTE carrier.

[0102] One requirement that must be considered when implementing NB-loT, particularly when doing so in inband and guardband deployment, is the requirement that the LTE and NB-loT transmissions are aligned in the time domain. Specifically, it is important that an NB-loT carrier signal, e.g. carrier signals 320, 330, 340, operate in the uplink (UL) direction when the LTE carrier signal 310 also operates in the UL direction. Likewise, it is important that an NB-loT carrier signal operates in the downlink (DL) direction when the LTE carriers signal also operates in the DL direction. This is to maintain the orthogonality requirement so as to prevent interference between the LTE and NB-loT communications. Under certain conditions, satisfying this requirement may be a challenge.

[0103] Reference is made to figure 4, which shows a table 400 of different configurations that may be applied for an LTE frame when using time division duplex (TDD). The term "configuration" may be understood to refer to the time periods assigned for downlink communication and uplink communication. Thus each configuration may, relative to other configurations, comprise a sequence of uplink subframes, downlink subframes, and subframes that are configured for transitioning between an uplink subframe and a downlink subframe. Time division duplex (TDD) refers to duplex communication links where the uplink transmissions are separated from the downlink transmissions by the allocation of different time slots in the same frequency band. TDD is a transmission scheme that allows asymmetric flow for uplink and downlink data transmission, in which a communication device is allocated respective time slots for uplink and downlink transmission. The first configuration, for example, that is shown in figure 4, shows that the communication device receives downlink subframes from the base station at subframe numbers 0 and 5, and transmits uplink subframes to the base station at subframe numbers 2, 3, 4, 7, 8, and 9. Subframe number 1 is a special subframe. A special subframe may be understood to be a subframe which is configured for switching between downlink transmissions and uplink transmissions. A special subframe is divided into 3 parts: the Downlink Pilot Time Slot (DwPTS), the Guard Period (GP) and the Uplink Pilot Time Slot (UpPTS). The GP compensates for the maximum propagation delay of interfering components. The GP implements the DL to UL transition point and, hence has to be large enough to cover the propagation delay of DL interferers. The DwPTS carries reference signals and control information and the primary synchronisation signal on the DL from the base station to the communication device. The UpPTS is used for sounding reference signal transmission from the user equipment to the base station.

[0104] As may be seen from figure 4, the maximum period of continuous uplink transmission is 3 subframes. Each subframe is 1ms in length. Therefore, at most, any NB-loT UL transmission must last no longer than 3m, so as to ensure that the LTE and NB-loT configurations remain aligned in the time domain. For certain types of transmission, this may be problem.

[0105] The Random access procedure is a procedure carried out by a communication device to establish connection with the access point of a wireless network. The Random access channel (RACH) is a shared channel used by such communication devices to access the network for the purposes of, for example, call set-up and bursty date transmission. The RACH is used for achieving uplink (UL) synchronization between UE and evolved base stations (also referred as eNodeB or eNB), and establishing connection with a network. [0106] The physical random access channel (P ACH) is a physical layer channel that is used by a communication device to access the network and to carry small data packets. The PRACH is composed of two different parts: the preamble part, and the message part that carries the RACH message. The preamble part provides an identification of the communication device that is transmitting the PRACH. A preamble for a channel may be understood to be a sequence of bits for achieving synchronisation.

[0107] Reference is made to figure 5, which shows an example of a random access symbol group 500 that may be transmitted in the uplink as part of the PRACH preamble during an N B-loT transmission using frequency division duplexing (FDD). In FDD, the transmitter and receiver operate at different carrier frequencies for transmissions occurring at the same time. The FDD N B-loT PRACH (NPRACH) preamble design is based on single-subcarrier frequency-hopping symbol groups. Each symbol group 500, as illustrated in figure 5, may comprise a cyclic prefix (CP) of length TC and a sequence of 5 identical symbols with a total length of TSEQ. A cyclic prefix is a prefix containing a part from the end of the symbol. Thus, the receiver can identify the end point of each symbol and correctly correlate the information, thereby eliminating intersymbol interference. Typical values for Tcp and Ts_eq for different preamble formats are listed in terms of LTE sampling time Ts (~ 32.55 ns) in Table 1.

Table 1: Random access preamble parameters

[0108] The PRACH preamble consists of four of the symbol groups 500 shown in figure 5, transmitted without time gaps between them. Effective FDD PRACH preamble durations for the two formats are given below in table 2.

Table 2: Effective FDD PRACH preamble durations

[0109] When deploying N B-loT in in-band or guardband mode for LTE communications that are transmitted according to TDD, it is not possible to introduce support for the N B-loT without also transmitting the N B-loT communications according to TDD. However, as may be seen from table 2, the durations (i.e. 5.6 ms and 6.4 ms) are such that they cannot fit into any of the U L configurations shown in figure 4. In other words, there is no configuration for LTE-TDD in which the duration of the UL transmissions carried out for LTE communications are long enough to allow for the transmission of the P ACH preamble.

[0110] Although this problem has been explained in the context of the protocols LTE, and N B-loT, it should be appreciated that the problem need not be limited to that context, and may occur in other contexts where part of an uplink channel , which needs to be transmitted, may not fit into the time period assigned for U L transmission. Furthermore, although the problem has been explained in the context of a physical random access channel preamble, it should be appreciated that the problem need not be limited to that context, and may occur in other contexts where part of an uplink channel , which needs to be transmitted may not fit into the time period assigned for U L transmission. The part of the uplink channel could be a PRACH preamble, a preamble of another channel type, or another form of information that is not a preamble. Examples of the application attempt to solve this problem.

[0111] One proposed solution to the problem, in the context of channel preambles, is to replace the usual channel preamble with two reduced size preambles (known as a "mini preambles") each having half the number of symbol groups. The two mini preambles could be transmitted in two consecutive U L reserved transmissions. Reducing the size in this way, would enable each of the resulting mini preambles to fit into some of the time periods (2ms and 3ms) reserved for U L in the TDD configurations shown in figure 4. However, this proposed solution has the disadvantage of leading to delays. Furthermore, even if the preamble size is reduced in this way, the size is still too great to enable the resulting mini preambles to be transmitted in the 1ms time periods, which in some cases is the only time reserved for UL in a particular LTE U L/DL configuration.

[0112] Another proposed solution to the problem is to alter the sub-carrier spacing so as to meet the timing requirements. However, for maximum reuse of N B-loT FDD design to N B-loT TDD configurations the subcarrier spacing cannot be altered and, therefore, the same concept of frequency hopped symbol group transmission needs to be used, with the same tone frequency of 3.75 KHz.

[0113] Another proposed solution is to replace the special subframe with an extended special subframe, where the special subframe is extended to 2 subframes (28 symbols) using the existing special subframe (14 symbols) and the existing next U L subframe (14 symbols) and granting more symbols for DL (as required). This allows more symbols for DL in DL restricted configuration.

[0114] Reference is made to figure 6, shows different possibilities for symbol group(s) that may be transmitted in a period assigned for U L transmission lasting only 1 ms. A first possible transmission 600 is shown. This transmission 600 comprises only one symbol group 610. The symbol group 610 comprises a cyclic prefix and 3 symbols. Each of the 3 symbols may be transmitted at a different tone frequency. This transmission 600 may be part of a channel preamble, with the remaining parts of the preamble being transmitted at a later point in time in different U L transmission windows. [0115] A second possible transmission 650 that may occur in a 1ms window is shown. This transmission 650 comprises a first symbol group 660, and a second symbol group 670. The first symbol group 660 and second symbol group 670 each comprise a cyclic prefix and one symbol. This transmission 650 may be part of a channel preamble, with the remaining parts of the preamble being transmitted at a later point in time in different UL transmission windows.

[0116] Reference is made to figure 7, which shows a possible transmission 700 for symbol group(s) that may be transmitted in a period assigned for U L transmission lasting 2 ms. This transmission 700 comprises a first symbol group 710, and a second symbol group 720. The first symbol group 710 and second symbol group 720 each comprise a cyclic prefix and two symbols. This transmission 700 may be part of a channel preamble, with the remaining parts of the preamble being transmitted at a later point in time in different U L transmission windows. The two symbol groups may be transmitted using frequency hopping, wherein the first symbol group 710 is transmitted at a first frequency, and the second symbol group 720 is transmitted at a second frequency, that is different to the first frequency.

[0117] Reference is made to figure 8, which shows a possible transmission 800 for symbol group(s) that may be transmitted in a period assigned for U L transmission lasting 3 ms. This transmission 800 comprises a first symbol group 810, and a second symbol group 820. The first symbol group 810 and second symbol group 820 each comprise a cyclic prefix and five symbols. This transmission 800 may be part of a channel preamble, with the remaining parts of the preamble being transmitted at a later point in time in different U L transmission windows. The two symbol groups may be transmitted using frequency hopping, wherein the first symbol group 810 is transmitted at a first frequency, and the second symbol group 820 is transmitted at a second frequency, that is different to the first frequency.

[0118] As seen from ta ble 2, in N B-loT there are two different preamble formats that may be used for a PRACH preamble. Format 0 uses a shorter cyclic prefix and, hence has a reduced duration compared to format 1, which uses a long cyclic prefix. If the transmissions 600, 650, 700, 800, that are shown in figure 6, 7, and 8 are sent according to format 1, and without using the method according to examples of the application that will be described, the time required for transmission will exceed the window size limits (either 1 ms, 2ms, or 3ms). This may be seen from table 3, wherein the additional transmission time required for these formats is shown. The additional transmission time required for format 1 is given in ta ble 3. As shown, an extra 0.066 ms beyond the 1 ms time window is needed to make transmissions 600 or 650, an extra 0.13 ms beyond the 2ms time window is needed to make the transmission 700, and an extra 0.2 ms beyond the 3ms time window is needed to make the transmission 800. PRACH Format Transmission time and Addition Additional time required (in terms time required ofTs)

PRACH 1ms - Format 1 (0.266 1.066 ms : 0.066 Additional 2028 Ts.

ms CP) transmission time

PRACH 2ms - Format 1 (0.266 2.133 ms : 0.13 msec Additional 3993 Ts

ms CP) Transmission time

PRACH 3ms - Format 1 (0.266 2.133 ms : 0.2 msec Additional 6144 Ts

ms CP) Transmission time

Table 3

[0119] According to examples of the application, a new special sub-frame may be used, which includes extra UL symbols for transmitting a first part of an uplink channel. By migrating some of the information of an uplink channel to the special subframe, the time duration of a second part of the uplink channel that is transmitted during the UL slots which follow the special subframe may be reduced to a level that allows it to be transmitted within a time period that is permitted for UL by the TDD configuration. The new special subframe may use the same length as a special subframe that is currently used for switching that doesn't include part of a part of an uplink channel. The new special subframe may consist of 14 symbols. The first part of the uplink channel may comprise a first part of a channel preamble. The second part of the uplink channel may comprise a second part of a channel preamble. Together, the first part of the uplink channel and the second part of the uplink channel may comprise a channel preamble. Alternatively, the first part of the uplink channel and the second part of the uplink channel may comprise part of a channel preamble. The channel preamble could be a PRACH preamble. In other cases, the preamble could be a preamble for other UL channels.

[0120] In some example, the first part of the uplink channel that is included in the special subframe may be part of a physical uplink shared channel (PUSCH). In some examples, the uplink part of the special subframe may comprise part of a first channel and part of a second channel. The first channel could, for example, be a PRACH, and the second channel could, for example, be a PUSCH.

[0121] According to examples, the base station may begin channel processing of the uplink channel from the start of the UL section (e.g. the start of the UpPTS) in the special subframe instead of at the start of the UL slot in UL-DL configuration. This processing may comprise PRACH processing in the case that the first part of the uplink channel comprises a part of a PRACH preamble.

[0122] In an example, an LTE system may determine a configuration to be used for a special subframe in dependence on a determination of what is to be transmitted in a NB-loT communication. This may result in having a special subframe configuration that is dependent on a transmissions to be made in a 2^nd protocol (NB -loT).

[0123] In some examples, the use of the modified special subframe in which at least part of the uplink channel is included in the subframe may be dynamically applicable. In other words, in the example of LTE, the modified special subframe may only be transmitted by the communication when followed by UL subframes where the channel is to be sent. After the communication device has transmitted the first and second part of the uplink channel, it may then revert to sending a special subframe without at least part of an uplink channel included in it. As will be explained, the special subframe with the first part of the uplink channel, and the special subframe without, may use different configurations. For the different configurations, different subcarrier spacing may be used.

[0124] In some examples, the use of the new special subframe may be combined with the use of reduced size preambles, which are transmitted in consecutive UL reserved transmissions.

[0125] The following example describe the case where the first part of the uplink channel comprises a first part of a channel preamble, and the second part of the uplink channel comprises a second part of a channel preamble. However, it would be understood that these are examples only, and that, in these examples, when a "channel preamble" is referred to, another part of an uplink channel, other than a channel preamble may be meant.

[0126] Therefore, referring back to figure 6, 7, and 8, to address this problem, and to allow the transmissions to be made within the permissible window size, at least part of the preamble may be transmitted during the special subframe preceding the UL transmissions, for example, transmission 600, 650, 700, 800. The at least part of the preamble may be transmitted as part of the UpPTS part of the special subframe. However, the existing special subframe configurations for TDD only provides 1 or 2 OFDM symbols for UpPTS. The special subframe configuration for TDD idle mode operation is given in table 4.

Table 4

[0127] Configurations 0 to 9 shown in table 4, have only 1 or 2 symbols reserved for UpPTS.

However, as may be seen from table 3, an additional period of up to 6144Ts (0.2 ms) may be required for the transmission of the preamble as part of the UpPTS part of the special subframe. For, the cases, where the transmission time window is only 1ms, the configurations 0 to 4 may provide a sufficient period of 1 UpPTS. For the cases where the transmission time window is 2ms, the configurations 5 to 9 may provide a sufficient period of 2 UpPTS. For, the cases, where the transmission time window is 3ms, configuration 10 may provide a sufficient period of 6 UpPTS.

[0128] Table 5 below shows a set of possible configurations for a modified special subframe that could be used to accomodate at least part of a PRACH preamble.

[0129] The configurations shown in table 5, typically have longer UpPTS duration than the special subframe configuration for TDD idle mode operation that are shown in table 4. To increase the number of uplink symbols in the special subframe, the number of downlink symbols may be reduced. By increasing the number of uplink symbols, enough of the channel preamble may be including in the uplink section of the special subframe, that the subsequent uplink transmissions after the special subframe are able to accommodate the remaining part of the channel preamble. The format 1 (having a long cyclic prefix) preamble may be used with all of the configurations shown in table 5, with the exception of configurations 3, 4, and 7. Configuration 3 GPP Number of OFDM symbols / subframe PRACH Formats release Dw GP Up

0 8 0 11 3 (7680.Ts) All (Format- 1 long CP)

1 8 7 4 3(7680.Ts) All (Format- 1 long CP)

2 8 8 3 3 (7680.Ts) All (Format- 1 long CP)

3 8 10 2 2 (5160.Ts) All (Format 0 with short CP)

4 8 12 1 1 All (Format 0 with short CP)

5 8 2 9 3 (7680.Ts) All (Format- 1 long CP)

6 8 8 3 3 (7680.Ts) All (Format- 1 long CP)

7 8 9 2 3 (7680.Ts) All (Format- 1 long CP)

8 8 11 1 2 (7680.Ts) All (Format 0 with short CP)

9 11 5 6 3(7680.Ts) All (Format- 1 long CP)

10 14 5 2 7(17920.Ts) All (Format- 1 long CP)

Table 5

[0130] To see how the special subframe configurations shown in table 5 have advantages over the special subframe configuration shown in table 4, consider the example of configuration 9 shown in both tables. In table 4, for configuration 9, the ratio of duration of DwPTS:GP:UpPTS = 6:6:2 symbols is used. Using this special subframe configuration, the channel 3ms format, that is exemplified in figure 8, may not be used as the remaining part of the preamble would not be able to fit into the period reserved for UL following the special subframe. However, if, instead of this configuration, the configuration 9 that is shown in table 5 - having DwPTS:GP:UpPTS = 5:6:3 - were used the 3ms format could be used, as the number of UL symbols available in the UL part of the special subframe are sufficient to support the 3ms format.

[0131] The base station that is configured to communicate with the communication device may be configured to broadcast an instruction to modify the special subframe configuration so as to allow transmission by the communication device of the channel preamble. Depending on the assigned special configuration and UL/DL configuration, the need for a modified special frame will vary. For example, if the UL/DL configuration is such that, in each frame, only one UL subframe is assigned, a lms format for transmitting the preamble, e.g. using transmissions 600 or 650, may be used. In this case, no modification to the special subframe configuration is needed, and the configurations 0 to 9 shown in table 4 may be used. In another example, if the channel format 0, having a shortened cyclic prefix, is used, the special subframe adjustment is not required.

[0132] The re-adjustment of the special subframe configuration to allow additional transmission time for the channel preamble can also be used if the channel design uses a 15 KHz tone as a channel frequency. In this case, an integral number of symbol group transmissions without having a GP within the uplink window is possible with the modified special subframe configuration. [0133] Although most of the configurations shown in table 5 do not exceed the allocation of 3 symbols for UL transmission, it is shown that some configurations may exceed this. For example, configuration 10 shown in the table, has DwPTS:GP:UpPTS = 1:6:7.

[0134] Dynamic adjustment of the durations of the uplink period and the downlink period may be carried out for the special subframe preceding the U L subframe configured for channel transmission. This may be done to enable transmission of the channel preamble whose length requires additional UL duration than is available in subframes assigned for uplink that follow the special subframe. Performing the dynamic adjustment may be done without impacting the special subframe configuration for transmissions according to other protocols (e.g. LTE) that may take place adjacent the transmission of the special subframe including part of the channel preamble. The dynamic adjustment could comprise switching between different special subframe configurations, for example, the configurations shown in table 4 and table 5.

[0135] When transmissions according to a first protocol (such as LTE) are made by a communication device also making transmissions according to a second protocol (such as N B-loT), a particular configuration for a special subframe used for the second protocol may be selected without impacting the interworking with the first protocol. In other words, the DwPTS and UpPTS duration may be selected so that the DL transmission of the special subframe according to the second protocol does not overlap with the uplink transmission according to the first protocol. Furthermore, the DwPTS and UpPTS duration may be selected so that the U L transmission of the special subframe according to the second protocol does not overlap with the downlink transmission according to the first protocol.

[0136] Reference is made to figure 9, which illustrates this. The figure shows a first special subframe 900 according to a first protocol (e.g. LTE), and a second special subframe 950 according to the second protocol (e.g. N B-loT). The second special subframe 950 may incorporate at least part of a channel preamble, which may be transmitted, in the U L part 960 (i.e. UpPTS) of the second special subframe 950. The duration of the downlink section 970 (i.e. DwPTS) of the second special subframe 950 and the duration of the uplink section 960 of the second special su bframe 950 may be chosen in dependence upon the duration of the downlink section 910 of the first special subframe 900 and the uplink section 920 of the first special subframe 900. Specifically, the durations may be selected such that there is at least a 1 symbol gap between the end of the downlink section 910 of the first special subframe 900 and the uplink section 960 of the second special subframe 950. The condition enables the second protocol base station (e.g. N B-loT base station) to switch to uplink reception only after the downlink transmission according to the first protocol stops. Hence, the problem of interference between the transmissions may be avoided. [0137] Similarly, the duration of the downlink transmission 970 of the second special subframe could be selected such that there is at least a one symbol gap between the end of the downlink transmission and the start of the uplink transmission 920 of the first special subframe. By selecting the durations of the downlink transmission 970 and the uplink transmission 960, overlap of the downlink transmission of one subframe and the uplink transmission of the other may be avoided.

[0138] Reference is made to figure 10, which shows an example of transmissions from a communication device that may take place over a time period according to an example. The communication device is configured to transmit a first special subframe 1010 comprising an U L part 1020. The U L part 1020 includes a first part of a channel preamble. Following the transmission of the special subframe 1010, the communication device is configured to transmit a second part 1030 of the channel preamble. The second part 1030 of the channel preamble may comprise one of the transmissions 600, 650, 700, and 800, shown in figures 6, 7, and 8. Following the UL transmission of the second part 1030 of the channel preamble, the communication device may be configured to receive downlink data 1040 from the base station.

[0139] The communication device is configured to, after receiving the downlink data 1040 from the base station and prior to switching back to UL mode, transmit another special subframe 1020 to the base station comprising an U L part 1060. The UL part 1060 includes a third part of a channel preamble. Following the transmission of the special subframe 1050, the communication device is configured to transmit a fourth part 1070 of the channel preamble. The fourth part 1070 of the channel preamble may comprise one of the transmissions 600, 650, 700, and 800, shown in figures 6, 7, and 9.

[0140] Together, the first part of the channel preamble, the second part 1030 of the channel preamble, the third part of the channel preamble, and the fourth part 1070 of the channel preamble may constitute a channel preamble. In other examples, the channel preamble may be divided into fewer than or more than 4 parts of the uplink channel.

[0141] Reference is made to figure 11 which shows a method that may be performed in a communication device according to examples of the application. It would be appreciated that this method is an example only, and that in some examples one or more steps may be excluded.

[0142] At S1110, the communication devices receives part of a special subframe. The received part of the subframe may comprise a DwPTS.

[0143] St S1120, after a gap period of no transmission or reception, the communication device transmits part of a special subframe to the base station. The transmitted part of the special subframe comprises a part of a channel preamble. The transmitted part of special subframe may comprise an UpPTS. [0144] At S1130, the communication device is then configured to transmit another part of the channel preamble to the base station. This part of the channel preamble may be divided into two or more separate parts that are transmitted at separate frequencies according to frequency hopping.

[0145] At S1140, the communication device is configured to receive downlink data from the base station.

[0146] In some examples, the method may repeat until the full channel preamble is transmitted by the communication device.

[0147] Reference is made to figure 12, which shows an example of a method that may be performed in a base station according to examples of the application. It would be appreciated that this method is an example only, and that in some examples one or more steps may be excluded.

[0148] At S1210, the base station transmits part of a special subframe. The transmitted part of subframe may comprise a DwPTS. The special subframe may correspond to a second protocol (e.g.

N B-loT). The timing of this special subframe may be aligned with the timing of a special subframe corresponding to a first protocol (e.g. LTE)

[0149] At S1220, after a gap period of no transmission or reception within the special subframe, the base station receives part of a special subframe. The received part of the special subframe comprises a part of a channel preamble. The received part of special su bframe may comprise an UpPTS.

[0150] At S1230, the base station may begin to process the channel preamble using the received part of the channel preamble contained in the special subframe.

[0151] At S1240, another part of the channel preamble is received at the base station. This part of the channel preamble may be divided into two or more separate parts that are transmitted at separate frequencies according to frequency hopping.

[0152] At S1250, the base station is configured to transmit downlink data to the communication device.

[0153] In some examples, the method may repeat until the full channel preamble is transmitted by the communication device.

[0154] Examples of the application have the advantage that by re-adjustment of the special subframe design, which may follow the design of N B-loT FDD, to include part of an uplink channel , improved resource efficiency is achieved. Any other formats will not have the same resource efficiency (CP overhead, Guard Period within subframe). The re-adjustment allows the transmission of the first and the second parts of the uplink channel within the complete uplink window.

[0155] It is noted that whilst examples have been described in relation to one example of a standalone LTE network and the use N B-loT, similar principles may be applied in relation to other examples of standalone 3G, LTE or 5G networks. It should be noted that other examples may be based on other cellular technology other than LTE or on variants of LTE. It should also be noted that other examples may be based on standards other than N B-loT or on variants of N B-loT. Therefore, although certain examples were described above by way of example with reference to certain example architectures for wireless networks, technologies and standards, examples may be applied to any other suitable forms of communication systems than those illustrated and described herein.

[0156] It is also noted herein that while the above describes example examples, there are several variations and modifications which may be made to the disclosed solution without departing from the scope of the present invention.

[0157] The method may additionally be implemented in a control apparatus as shown in Figure 13. The method may be implemented in a single processor 201 or control apparatus or across more than one processor or control apparatus. Figure 13 shows an example of a control apparatus 1300 for a communication system, for example to be coupled to and/or for controlling a station of an access system, such as a RAN node, e.g. a base station, (e) node B, a central unit of a cloud architecture or a node of a core network such as an MME or S-GW, a scheduling entity such as a spectrum management entity, or a server or host. The control apparatus may be integrated with or external to a node or module of a core network or RAN. In some examples, base stations comprise a separate control apparatus unit or module. In other examples, the control apparatus can be another network element such as a radio network controller or a spectrum controller. In some examples, each base station may have such a control apparatus as well as a control apparatus being provided in a radio network controller. The control apparatus 1300 can be arranged to provide control on

communications in the service area of the system. The control apparatus 1300 comprises at least one random access memory 1310, at least one read only memory 1350 at least one data processing unit 1320, 1330 and an input/output interface 1340. The at least one random access memory 1310 and the at least one read only memory 1350 are in communication with the at least one data processing unit 1320, 1330. Via the interface, the control apparatus can be coupled to a receiver and a transmitter of the base station. The receiver and/or the transmitter may be implemented as a radio front end or a remote radio head. For example, the control apparatus 1300 or processor 201 can be configured to execute an appropriate software code to provide the control functions.

[0158] Control functions may comprise causing the transmission of a first part of an uplink channel in a first subframe that is configured for switching between a downlink mode and an uplink mode; and causing the transmission of a second part of the uplink channel in at least one subframe immediately adjacent to the first subframe.

[0159] Alternatively, or in addition, control functions may comprise receiving a first part of an uplink channel in a first subframe that is configured for switching between a downlink mode and an uplink mode; and receiving a second part of the uplink channel in at least one subframe immediately adjacent to the first subframe.

[0160] It should be understood that the apparatuses may comprise or be coupled to other units or modules etc., such as radio parts or radio heads, used in or for transmission and/or reception.

Although the apparatuses have been described as one entity, different modules and memory may be implemented in one or more physical or logical entities.

[0161] In general, the various examples may be implemented in hardware or special purpose circuits, software, logic or any combination thereof. Some aspects of the invention may be implemented in hardware, while other aspects may be implemented in firmware or software which may be executed by a controller, microprocessor or other computing device, although the invention is not limited thereto. While various aspects of the invention may be illustrated and described as block diagrams, flow charts, or using some other pictorial representation, it is well understood that these blocks, apparatus, systems, techniques or methods described herein may be implemented in, as non-limiting examples, hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controller or other computing devices, or some combination thereof.

[0162] The examples of this invention may be implemented by computer software executable by a data processor of the mobile device, such as in the processor entity, or by hardware, or by a combination of software and hardware. Computer software or program, also called program product, including software routines, applets and/or macros, may be stored in any apparatus-readable data storage medium and they comprise program instructions to perform particular tasks. A computer program product may comprise one or more computer-executable components which, when the program is run, are configured to carry out examples. The one or more computer-executable components may be at least one software code or portions of it.

[0163] Further in this regard it should be noted that any blocks of the logic flow as in the Figures may represent program steps, or interconnected logic circuits, blocks and functions, or a combination of program steps and logic circuits, blocks and functions. The software may be stored on such physical media as memory chips, or memory blocks implemented within the processor, magnetic media such as hard disk or floppy disks, and optical media such as for example DVD and the data variants thereof, CD. The physical media is a non-transitory media. An example of a non-transitory computer readable medium 1400 is shown in figure 14. The non-transitory computer readable medium 1400 may be a CD or DVD.

[0164] The memory may be of any type suitable to the local technical environment and may be implemented using any suitable data storage technology, such as semiconductor based memory devices, magnetic memory devices and systems, optical memory devices and systems, fixed memory and removable memory. The data processors may be of any type suitable to the local technical environment, and may comprise one or more of general purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs), application specific integrated circuits (ASIC), FPGA, gate level circuits and processors based on multi core processor architecture, as non- limiting examples.

[0165] Examples of the inventions may be practiced in various components such as integrated circuit modules. The design of integrated circuits is by and large a highly automated process. Complex and powerful software tools are available for converting a logic level design into a semiconductor circuit design ready to be etched and formed on a semiconductor substrate.

[0166] The foregoing description has provided by way of non-limiting examples a full and informative description of the exemplary example of this invention. However, various modifications and adaptations may become apparent to those skilled in the relevant arts in view of the foregoing description, when read in conjunction with the accompanying drawings and the appended claims. However, all such and similar modifications of the teachings of this invention will still fall within the scope of this invention as defined in the appended claims. Indeed there is a further example comprising a combination of one or more examples with any of the other examples previously discussed.

Claims

1. A method comprising:

transmitting a first part of an uplink channel in a first subframe that is configured for switching between a downlink mode and an uplink mode; and

transmitting a second part of the uplink channel in at least one subframe immediately adjacent to the first subframe.

2. A method as claimed in claim 1, comprising transmitting part of a further uplink channel in the first subframe.

3. A method as claimed in claim 2, wherein the further uplink channel is a physical uplink shared channel.

4. A method as claimed in any preceding claim, wherein the transmissions of the first part of the uplink channel and the second part of the uplink channel are made according to narrow band internet of things.

5. A method as claimed in any preceding claim, wherein the first part of the uplink channel and the second part of the uplink channel comprise at least part of a physical random access channel preamble.

6. A method as claimed in any preceding claim, wherein the transmissions of the first part of the uplink channel and the second part of the uplink channel are made in one of: in band mode of operation or guardband mode of operation.

7. A method as claimed in any preceding claim, comprising:

dynamically adjusting the configuration of subframes that are configured for switching between a downlink mode and an uplink mode.

8. A method as claimed in claim 7, comprising:

transmitting the subframes that are configured for switching between a downlink mode and an uplink mode in a first configuration when each of the subframes comprise a part of an uplink channel; and transmitting the subframes that are configured for switching between a downlink mode and an uplink mode in a second configuration when the subframes do not comprise a part of an uplink channel.

9. A method as claimed in claim 8, wherein the first configuration comprises a greater number of symbols reserved for uplink transmission than the second configuration.

10. A method as claimed in any preceding claim, wherein the transmissions of the first part of the uplink channel and the second part of the uplink channel comprise transmissions according to a second protocol, the method further comprising:

transmitting and receiving data according to a first protocol,

wherein the data transmitted according to the first protocol is aligned in time with the transmissions according to the second protocol.

11. A method as claimed in claim 10, wherein the data transmitted and received according to the first protocol comprises a second subframe that is configured for switching between a downlink mode and an uplink mode, wherein the difference in time between an end of the downlink received data in the second subframe and the start of the uplink transmission in the first subframe is at least one symbol.

12. A method comprising:

receiving a first part of an uplink channel in a first subframe that is configured for switching between a downlink mode and an uplink mode; and

receiving a second part of the uplink channel in at least one subframe immediately adjacent to the first subframe.

13. A computer program comprising instructions such that when the computer program is executed on a computing device provides a method, the computing device is arranged to perform the steps of any of claims 1 to 12.

14. An apparatus comprising:

at least one processor and at least one memory including computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to: transmit a first part of an uplink channel in a first subframe that is configured for switching between a downlink mode and an uplink mode; and

transmit a second part of the uplink channel in at least one subframe immediately adjacent to the first subframe.

15. An apparatus comprising:

at least one processor and at least one memory including computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to:

receive a first part of an uplink channel in a first subframe that is configured for switching between a downlink mode and an uplink mode; and

receive a second part of the uplink channel in at least one subframe immediately adjacent to the first subframe.