WO2013131262A1

WO2013131262A1 - Method and apparatus for providing system information for limited-bandwidth devices

Info

Publication number: WO2013131262A1
Application number: PCT/CN2012/072079
Authority: WO
Inventors: Wei Bai; Shuang TAN; Na WEI; Jing HAN; Chunyan Gao; Haiming Wang
Original assignee: Renesas Mobile Corp
Current assignee: Renesas Electronics Corp
Priority date: 2012-03-08
Filing date: 2012-03-08
Publication date: 2013-09-12
Anticipated expiration: 2014-09-08

Abstract

A method, apparatus, and computer program product are provided to provide system information for limited-bandwidth devices. In the context of a method, a System Information Block type 1 (SIB-1) may be prepared. The method may include allocating resources for the SIB-1 and causing the SIB-1 to be transmitted to a limited-bandwidth device using the allocated resources. The resources may be allocated according to a fixed scheme, a hopping scheme, or a blind decoding scheme. Also in the context of a method, an SIB (type 1 or otherwise) may be prepared so as to include bandwidth-independent information which may be directly read by a receiving device, and information related to bandwidth-dependent information options, such that bandwidth-dependent information may be indirectly read using the information regarding the bandwidth-dependent information options.

Description

METHOD AND APPARATUS FOR PROVIDING SYSTEM INFORMATION FOR

LIMITED-BANDWIDTH DEVICES

TECHNOLOGICAL FIELD

[0001] An example embodiment of the present invention relates generally to wireless networks and, more particularly, to providing system information for limited-bandwidth devices.

BACKGROUND

[0002] As Long Term Evolution (LTE) deployments evolve, network operators would like to reduce the cost of overall network maintenance by minimising the number of Radio Access Technologies (RATs) mat they must maintain. However, networks operators are also seeing an accelerating proliferation of Machine-Type Communications (MTQ devices which rely primarily on Global System for Mobile Communications (GSM)/ General Packet Radio Service (GPRS) RATs, instead of LTE.

[0003] MTC devices usually target low-end (low cost, low data rate) applications that can be handled adequately by GPRS on the 2^nd Generation (2G) and 3^rd Generation (3G) GSM networks. Owing to the low cost of these devices and good coverage of GSM GPRS, there is very little motivation for MTC device suppliers to use modules supporting the LTE radio interface. As more and more MTC devices are deployed in the field, this naturally increases the reliance on GSM GPRS networks. Not only will maintaining GSM GPRS networks in addition to LTE networks cost operators more, the non-optimal spectrum efficiency of GSM/GPRS will also prevent operators from reaping the maximum benefit of their allocated spectrum. Given the high number of MTC devices currently deployed and likely to be deployed in the future, the overall resources that network operators will need for service provision may be both significant and inefficiently assigned.

[0004] Thus, solutions are needed to ensure easy and cost-effective migration of MTC devices from GSM/GPRS to LTE networks.

BRIEF SUMMARY

[0005] Therefore, a method, apparatus, and computer program product are provided according to an example embodiment in order to provide system information to limited- bandwidth devices. In this regard, the method, apparatus, and computer program product may prepare System Information Blocks (STBs) for reception by all limited-bandwidth devices, regardless of their particular bandwidth capabilities. A way of allocating resources for an SD3-1 is also provided. The various embodiments thus provide an efficient way to provide system information to limited-bandwidth devices.

[0006] In one embodiment, a method is provided that includes receiving a system information block (SIB) at a limited-bandwidth device, the SIB comprising bandwidth- independent information and information related to one or more bandwidth-dependent information options. The method further includes reading the bandwidth-independent information directly and reading bandwidth-dependent information indirectly by using the information related to the one or more bandwidth-dependent information options. In another embodiment, a method is provided that includes preparing an SIB, allocating resources for the SIB, and causing the SIB to be transmitted to a limited-bandwidth device using the allocated resources. In another embodiment, allocating resources for the SIB involves allocating resources according to either a fixed scheme, a hopping scheme, or a blind decoding scheme. According to yet another embodiment preparing the SIB includes causing bandwidth-independent information and information related to one or more bandwidth-dependent information options to be included in the SIB. In another embodiment, preparing the SIB includes causing scheduling information for subsequent SIBs to be included in the SIB. The scheduling information includes one or more of a periodicity, a frequency resource allocation, or a modulation and coding scheme (MCS).

[0007] In a further embodiment, an apparatus is provided that includes at least one processor and at least one memory storing computer program instruction therein, the memory and computer program instructions being configured to, with the at least one processor, cause the apparatus to at least receive a system information block (SIB) at a limited-bandwidth device, the SIB comprising bandwidth-independent information and information related to one or more bandwidth-dependent information options. The apparatus is further caused to read the bandwidth-independent information directly and read bandwidth-dependent information indirectly by using the information related to the one or more bandwidth-dependent information options. In another embodiment, an apparatus is provided that includes at least one processor and at least one memory storing computer program instruction therein, the memory and computer program instructions being configured to, with the at least one processor, cause the apparatus to at least prepare an SIB, allocate resources for the SIB, and cause the SIB to be transmitted to a limited-bandwidth device using the allocated resources. The apparatus of this embodiment is caused to allocate resources for the SIB according to either a fixed scheme, a hopping scheme, or a blind decoding scheme. According to another embodiment, the apparatus is caused to prepare the SIB by causing bandwidth-independent information and information related to one or more bandwidth-dependent information options to be included in the SIB. In yet another embodiment, the apparatus is caused to prepare the SIB by causing scheduling information for subsequent SIBs to be included in the SIB. The scheduling information includes one or more of a periodicity, a frequency resource allocation, or a modulation and coding scheme (MCS).

[0008] In a further embodiment, a computer program product is provided that includes a non- transitory computer readable medium storing computer program instructions therein, the computer program instructions being configured to, upon execution, cause an apparatus to at least receive a system information block (SIB) at a limited-bandwidth device, the SIB

comprising bandwidth-independent information and information related to one or more bandwidth-dependent information options. The computer program instructions are further configured to, upon execution, cause the apparatus to read the bandwidth-independent

information directly and read bandwidth-dependent information indirectly by using the information related to the one or more bandwidth-dependent information options. In another embodiment, a computer program product is provided that includes a non-transitory computer readable medium storing computer program instructions therein, the computer program

instructions being configured to, upon execution, cause an apparatus to at least prepare an SIB, allocate resources for the SIB, and cause the SIB to be transmitted to a limited-bandwidth device using the allocated resources. The computer program instructions of this embodiment are configured to cause the apparatus to allocate resources for the SIB according to either a fixed scheme, a hopping scheme, or a blind decoding scheme. According to another embodiment, the computer program instructions are configured to, upon execution, cause the apparatus to prepare the SIB by causing bandwidth-independent information and information related to one or more bandwidth-dependent information options to be included in the SIB. In yet another embodiment, the computer program instructions are configured to, upon execution, cause the apparatus to prepare the SIB by causing scheduling information for subsequent SIBs to be included in the SIB. The scheduling information includes one or more of a periodicity, a frequency resource allocation, or a modulation and coding scheme (MCS).

[0009] In a further embodiment, an apparatus is provided that includes means for receiving a system information block (SIB) at a limited-bandwidth device, the SIB comprising bandwidth- independent information and information related to one or more bandwidth-dependent information options. The apparatus further includes means for reading the bandwidth- independent information directly and means for reading bandwidth-dependent information indirectly by using the information related to the one or more bandwidth-dependent information options. In another embodiment, an apparatus is provided that includes means for preparing an SIB, means for allocating resources for the SIB, and means for causing the SIB to be transmitted to a limited-bandwidth device using the allocated resources. In another embodiment, the means for allocating resources for the SIB include means for allocating resources according to either a fixed scheme, a hopping scheme, or a blind decoding scheme. According to yet another embodiment the means for preparing the SIB include means for including causing bandwidth- independent information and information related to one or more bandwidth-dependent information options to be included in the SIB. In another embodiment, the means for preparing the SIB include means for causing scheduling information for subsequent SIBs to be included in the SIB. The scheduling information includes one or more of a periodicity, a frequency resource allocation, or a modulation and coding scheme (MCS).

BRIEF DESCRIPTION OF THE DRAWINGS

[00 10] Having thus described certain example embodiments of the present d sclosure in general terms, reference will now be made to the accompanying drawings, which are not necessarily drawn to scale, and wherein:

[0011] Figure 1 is an illustration of a system depicting communications between a communication device and a network via a base station in which system information may be provided in accordance with an example embodiment of the present invention;

[00 12] Figure 2 is a block diagram of an apparatus that may be configured in accordance with an example embodiment of the present invention;

[00 13] Figure 3 is a diagram depicting a frequency spectrum supported by example full and limited-bandwidth devices; [0014] Figure 4 is a flowchart depicting the operations performed by an apparatus embodied by or otherwise associated with a limited-bandwidth device in accordance with an embodiment of the present invention;

[00 1 5] Figure 5 is a flowchart depicting the operations performed by an apparatus embodied by or otherwise associated with a base station in accordance with an embodiment of the present invention',

[0016] Figure 6 is a diagram depicting an example of a fixed resource allocation scheme for transmitting a system information block in accordance with an embodiment of the present invention; and

[0017] Figure 7 is a diagram depicting an example of a pre-defined hopping pattern resource allocation scheme for transmitting a system information block in accordance with an

embodiment of the present invention.

DETAILED DESCRIPTION

[00 18] The present invention now will be described more fully hereinafter with reference to the accompanying drawings, in which some, but not all embodiments of the inventions are shown. Indeed, these inventions may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will satisfy applicable legal requirements. Like numbers refer to like elements throughout.

[00 1 ] As used in this application, the term "circuitry" refers to all of the following:

(a)hardware-only circuit implementations (such as implementations in only analog and/or digital circuitry) and (b) to combinations of circuits and software (and or firmware), such as (as applicable): (i) to a combination of processors) or (ii) to portions of processor(s)/software (including digital signal processors)), software, and memory(ies) mat work together to cause an apparatus, such as a mobile phone or server, to perform various functions) and

(c) to circuits, such as a microprocessors) or a portion of a microprocessors), that

require software or firmware for operation, even if the software or firmware is not

physically present.

[0020] This definition of "circuitry" applies to all uses of this term m this application, including in any claims. As a further example, as used in this application, the term "circuitry" would also cover an implementation of merely a processor (or multiple processors) or portion of a processor and its (or their) accompanying software and/or firmware. The term "circuitry" would also cover, for example and if applicable to the particular claim element, a baseband integrated circuit or application specific integrated circuit for a mobile phone or a similar integrated circuit in a server, a cellular network device, or other network device.

[002 1] Referring now to Figure 1 , a system that supports communications between a limited- bandwidth communication device 1 and a network 14, such as a Universal Mobile

Telecommunications System (UMTS) network, a Long Term Evolution (LTE) network, an LTE- Advanced (LTE- A) network, a Global Systems for Mobile communications (GSM) network, a Code Division Multiple Access (CDMA) network, e.g., a Wideband CDMA (WCDMA) network, a CDMA2000 network or the like, a General Packet Radio Service (GPRS) network or other type of network, via a base station 12 is shown. As used herein, a limited-bandwidth device refers to any communication device which supports, e.g., is capable of communicating over, some subset of the entire available bandwidth of a network. Various types of limited-bandwidth devices may be employed including, for example, a mobile communication device such as, for example, a mobile telephone, portable digital assistant (PDA), pager, laptop computer, a tablet computer, or any of numerous other hand held or portable communication devices, computation devices, content generation devices, content consumption devices, data card, Universal Serial Bus (USB) dongle, or combinations thereof. Limited-bandwidth devices may also include, for example, Machine-Type Communications (MTC) devices which communicate through a network 14 without human intervention. Regardless of the type of limited-bandwidth device, it may communicate with the network via a base station 12, such as a Node B, an evolved Node B (eNB), a relay node, or other type of access point. The communications between the limited- bandwidth device 10 and the base station 12 may include the transmission of data via an uplink that is granted between the limited-bandwidth device 10 and the base station 12. The

communication session between the limited-bandwidth device 10 and the base station 12 may also be configured according to system information broadcast by the base station 12 and received and read by the limited-bandwidth device 10. The base station 12 may also simultaneously be in communication with other devices, such as full-bandwidth user equipment 11, which support, e.g., are capable of communicating over, the entire available bandwidth of the network 14. [0022] The limited-bandwidth device 10 and the base station 12 may embody or otherwise be associated with an apparatus 20 that is generally depicted in Figure 2 and that may be configured in accordance with an example embodiment of the present invention as described below. However, it should be noted that the components, devices or elements described below may not be mandatory and thus some may be omitted in certain embodiments. Additionally, some embodiments may include further or different components, devices or elements beyond those shown and described herein.

[0023] As shown in Figure 2, the apparatus 20 may include or otherwise be in

communication with processing circuitry, such as the processor 20 and, in some embodiments, the memory 24, which is configurable to perform actions in accordance with example embodiments described herein, such as in conjunction with Figures 4 and 5. The processing circuitry may be configured to perform data processing, application execution and/or other processing and management services according to an example embodiment of the present invention. In some embodiments, the apparatus or the processing circuitry may be embodied as a chip or chip set In other words, the apparatus or the processing circuitry may comprise one or more physical packages (e.g., chips) including materials, components and/or wires on a structural assembly (e.g., a baseboard). The structural assembly may provide physical strength,

conservation of size, and/or limitation of electrical interaction for component circuitry included thereon. The apparatus or the processing circuitry may therefore, in some cases, be configured to implement an embodiment of the present invention on a single chip or as a single "system on a chip." As such, in some cases, a chip or chipset may constitute means for performing one or more operations for providing the functionalities described herein.

[0024] In an example embodiment, the processing circuitry may include a processor 22 and memory 24 that may be in communication with or otherwise control a communication interface 26 and, in some cases in which the apparatus is embodied by the limited-bandwidth device 10, a user interface 28. As such, the processing circuitry may be embodied as a circuit chip (e.g., an integrated circuit chip) configured (e.g., with hardware, software or a combination of hardware and software) to perform operations described herein. However, in some embodiments taken in the context of the limited-bandwidth device 10 or the base station 12, the processing circuitry may be embodied as a portion of the limited-bandwidth device or the base station. [002S] In embodiments where the apparatus 20 is embodied by a limited-bandwidth device

10 configured to be interacted with by a user, the user interface 28 ma be in communication with the processing circuitry to receive an indication of a user input at the user interface and/or to provide an audible, visual, mechanical or other output to the user. Thus, the user interface may include, for example, a keyboard, a mouse, a joystick, a display, a touch screen, a microphone, a speaker, and/or other input/output mechanisms.

[0026] The communication interface 26 may include one or more interface mechanisms for enabling communication with other devices and/or networks. In some cases, the communication interface may be any means such as a device or circuitry embodied in either hardware, or a combination of hardware and software that is configured to receive and/or transmit data from to a network 14 and or any other device or module in communication with the processing circuitry, such as between the limited-bandwidth device 10 and the base station 12. In mis regard, the communication interface may include, for example, an antenna (or multiple antennas), such as an antenna (or multiple antennas) capable of communicating over radio frequencies (RF), and supporting hardware and/or software, such as RF circuitry, for enabling conimuni cations with a wireless communication network. The communication interface 26 may also or alternatively include a communication modem or other hardware/software for supporting communication via cable, digital subscriber line (DSL), universal serial bus (USB), Ethernet or other methods.

[0027] In an example embodiment, the memory 24 may include one or more non-transitory memory devices such as, for example, volatile and/or non-volatile memory that may be either fixed or removable. The memory may be configured to store information, data, applications, instructions or the like for enabling the apparatus 20 to carry out various functions in accordance with example embodiments of the present invention. For example, the memory could be configured to buffer input data for processing by the processor 22. Additionally or alternatively, the memory could be configured to store instructions for execution by the processor. As yet another alternative, the memory may include one of a plurality of databases that may store a variety of files, contents or data sets. Among the contents of the memory, applications may be stored for execution by the processor in order to carry out the functionality associated with each respective application. In some cases, the memory may be in communication with the processor via a bus for passing information among components of the apparatus. [0028] The processor 22 may be embodied in a number of different ways. For example, the processor may be embodied as various processing means such as one or more of a

microprocessor or other processing element, a coprocessor, a controller or various other computing or processing devices including integrated circuits such as, for example, an ASIC (application specific integrated circuit), an FPGA (field programmable gate array), DSP (digital signal processor), or the like. In an example embodiment, the processor may be configured to execute instructions stored in the memory 24 or otherwise accessible to the processor. As such, whether configured by hardware or by a combination of hardware and software, the processor may represent an entity (e.g., physically embodied in circuitry - in the form of processing circuitry) capable of performing operations according to embodiments of the present invention while configured accordingly. Thus, for example, when the processor is embodied as an ASIC, FPGA, DSP or the like, the processor may be specifically configured hardware for conducting the operations described herein. Alternatively, as another example, when the processor is embodied as an executor of software instructions, the instructions may specifically configure the processor to perform the operations described herein.

[0029] Figures 4 and 5 are flowcharts illustrating the operations performed by a method, apparatus and computer program product, such as apparatus 20 of Figure 2 in accordance with an example embodiment of the present invention as embodied by a base station 2 and a limited- bandwidth device 10, respectively. It will be understood that each block of the flowcharts, and combinations of blocks in the flowcharts, may be implemented by various means, such as hardware, firmware, processor, circuitry and/or other device associated with execution of software including one or more computer program instructions. For example, one or more of the procedures described above may be embodied by computer program instructions. In this regard, the computer program instructions which embody the procedures described above may be stored by a memory 24 of an apparatus employing an embodiment of the present invention and executed by a processor 22 in the apparatus. As will be appreciated, any such computer program instructions maybe loaded onto a computer or other programmable apparatus (e.g., hardware) to produce a machine, such that the resulting computer or other programmable apparatus provides for implementation of the functions specified in the flowchart blocks. These computer program instructions may also be stored in a non-transitory computer-readable storage memory that may direct a computer or other programmable apparatus to function in a particular manner, such that the instructions stored in the computer-readable storage memory produce an article of manufacture, the execution of which implements the function specified in the flowchart blocks. The computer program instructions may also be loaded onto a computer or other programmable apparatus to cause a series of operations to be performed on the computer or other programmable apparatus to produce a computer-implemented process such that the instructions which execute on the computer or other programmable apparatus provide operations for implementing the functions specified in the flowchart blocks. As such, the operations of Figures 4 and 5, when executed, convert a computer or processing circuitry into a particular machine configured to perform an example embodiment of the present invention. Accordingly, the operations of Figures 4 and S define an algorithm for configuring a computer or processing circuitry, e.g., processor, to perform an example embodiment. In some cases, a general purpose computer may be provided with an instance of the processor which performs the algorithm of Figures 4 and 5 to transform the general purpose computer into a particular machine configured to perform an example embodiment.

[0030] Accordingly, blocks of the flowcharts support combinations of means for performing the specified functions and combinations of operations for performing the specified functions. It will also be understood that one or more blocks of the flowcharts, and combinations of blocks in the flowcharts, can be implemented by special purpose hardware-based computer systems which perform the specified functions, or combinations of special purpose hardware and computer instructions.

[003 1] In some embodiments, certain ones of the operations above may be modified or further amplified as described below. Moreover, in some embodiments additional optional operations may also be included, some of which are shown in dashed lines in Figures 4 and 5. It should be appreciated mat each of the modifications, optional additions or amplifications below may be included with the operations above either alone or in combination with any others among the features described herein.

[0032] As discussed in the Background, the proliferation of Machine-Type Communications (MTC) devices has led to increased interest in migrating these devices to more efficient networks, such as LTE networks. However, the nature of MTC devices can make this process difficult. For instance, one of the most common ways to reduce the cost of MTC devices is to reduce their supported bandwidth to some subset of the full bandwidth available on the network. In this regard, Figure 3 depicts the full available frequency spectrum of an example LTE network. A full-bandwidth device operating on an LTE network would support all 20MHz of the available bandwidth 33. Limited-bandwidth devices would support a subset of the available 20Mhz of bandwidth 33. For example, a limited-bandwidth device may support SMhz of bandwidth 32,

1.4Mhz of bandwidth 3 1 , or any other subset of the full 20MHz bandwidth 33. Because limited- bandwidth devices cannot access resources outside of their supported bandwidth, special design accommodations must be made for them to operate effectively.

[0033] For example, issues can arise when limited devices need to read system information (SI) to camp in a cell and obtain configuration information. Full-bandwidth devices, such as full- bandwidth user equipment (UE) 1 1, first read the Master Information Block (MIB) to obtain the downlink (DL) bandwidth of the cell, Physical Hybrid Automatic Repeat Request Indicator Channel (PHICH) configuration information, and the System Frame Number (SFN). The full- bandwidth UE 1 1 then tries to detect the Physical Downlink Control Channel (PDCCH) addressed to the System Information- Radio Network Temporary Identifier (SI-RNTI) in order to read the System Information Block Typel (SIB-1). SHB-1 contains important cell access related information, such as the Public Land Mobile Network (PLMN) identity list, tracking area information, cell identity, etc. SIB-1 also contains the scheduling information for other SI blocks (SIBs). Limited-bandwidth devices, however, may not be able to receive and decode SIB-1 because it can be scheduled and transmitted on the whole bandwidth.

[0034] Thus, there are two possible straightforward solutions for this issue, both of which may have drawbacks. The first option is for the base station 12 to only send SIB-1 and other SIBs in the Physical Resource Blocks (PRBs) which falls into the bandwidth of limited- bandwidth devices with the narrowest bandwidth, and to then have the limited-bandwidth device decode the Enhanced-PDCCH (E-PDCCH) to locate the SIB. For example, a system may have a mix of limited-bandwidth devices, the narrowest of which supports 1.4MHz. A bandwidth of

1.4MHz encompasses only 6 PRBs in any given subframe. See item 31 of Figures 3 and 6.

Therefore, the SI must be transmitted in the central 6 PRBs to make it accessible to all the devices. Considering such a restricted resource, frequency selective scheduling could achieve quite little gain, so having the limited-bandwidth device monitor the E-PDCCH to get the resource allocation for SIBs would only add unnecessary overhead from the perspective of signaling and device power consumption. Considering only SIB-1 for example, its payload size is 120 bits if we do not consider optional fields. If we consider the channel coding with 1/3 coding rate and 24 bit Cyclic Redundancy Check (CRC), the channel bits should be

(120+24)*3=432 bits. Thus, assuming Quadradture Phase Shift Keying (QPSK) is used, there will be 216 symbols to carry. Given that one PRB has 108 Resource Eelements (REs) ((14-3)* 12 - 12 Demodualtion Reference Signal (DMRS) -12 Common Reference Signal CRS) available for Physical Downlink Shared Channel (PDSCH) transmission, two PRBs will be needed to carry the SEB-1. However, in current LTE systems, a PDCCH sent in the common search space only has an aggregation level of 4 or 8. This means that if an aggregation level of 4 is applied, the PDCCH will be mapped to 4 Control Channel Elements (CCEs) which has the same size as one PRB. If an aggregation level of 8 is applied, the PDCCH will be mapped to 8 CCEs, which has the size of two PRBs. Thus, the overhead of the E-PDCCH will be same as the payload size of the data.

[003 5] The second possible solution is to have the base station send separate SIBs for limited-bandwidth devices which have different bandwidth capability. In other words, different kinds of devices will monitor Physical Downlink Control Channel PDCCH or Enhanced Physical Downlink Control Channel E-PDCCH to get the resource allocation of its own SIB within the bandwidth it supports, and then read the system information according to the indication.

However, providing different SIBs for each different bandwidth capability would create a large signaling overhead. For example, if there are limited-bandwidth devices supporting 1 ,4MHz, 3MHz, and 5MHz bandwidths in a 20MHz LTE carrier, four separate SIBs would be required to be transmitted in order to support each bandwidth capability.

[0036] Therefore, referring now to Figure 4, the operations performed by a method, apparatus, and computer program product of an example embodiment are illustrated from the perspective of an apparatus 20 that may be embodied by or otherwise associated with the base station 12 in order to avoid the drawbacks of these possible solutions. In this regard, the apparatus may include means, such as the processing circuitry, the processor 22, the memory 24, the communications interface 26 or the like, for preparing a system information block (SIB), such as a SIB-1. See block 40 of Figure 4. It should be understood that the SIB-1 prepared by the apparatus 20, as well as subsequent SIBS discussed below, may in some embodiments be limited-bandwidth dedicated SIBs. That is, the SIBs described herein may, in some embodiments, be intended only for reception by limited-bandwidth devices. The apparatus 20 may cause scheduling information for one or more subsequent SUBs, such as a SIB type-2, type-3, etc., to be included in the SIB-1. See block 41 . This scheduling information may include one or more of the periodicity, frequency resource allocation, and/or a modulation and coding scheme (MCS). In one example embodiment, the scheduling information may include all three, i.e., a periodicity, a frequency resource allocation, and a MCS. The scheduling information may apply to one, more, or all of the subsequent SIBs. The MCS may be a single MCS or a plurality of possible MCSs. The apparatus may also optionally include E-control channel configuration information in the SIB-1. See block 41b. The E-control channel configuration information may include, for example, E-PDCCH configuration information or enhanced PHICH (E-PHICH) configuration information.

[0037] The apparatus 20 may also cause information to be made available to a limited- bandwidth receiving device 10 through the SIB in different ways depending on whether the information is bandwidth-independent or bandwidth-dependent. See block 41c. Bandwidth- independent information is any data, such as system information, configuration data or the like, that does not depend on or is otherwise irrelevant to the bandwidth capabilities of the receiving device. Bandwidth-dependent information is any information, such as system information, configuration data or the like, that depends on or is otherwise relevant to the bandwidth capabilities of the receiving device. For example, considering only SIB-2 for a moment, Bandwidth-independent information may include, for example, ac-Barringlnfo and

timeAlignmentTimerCommon, while Bandwidth-dependent information may include, for example, radioResourceConfigCommon and freqlnfo. Further examples of bandwidth- independent and dependent information are provided in 3GPP TS36.331, section 6.3.1.

According to one embodiment, the apparatus may cause bandwidth-independent information to be included in the SIB. See block 41c. Thus, a receiving device, such as a limited-bandwidth device 10, may directly read the bandwidth-independent information from the SIB- 1. The apparatus 20 may also cause information relating to one or more bandwidth-dependent information options to be included in the SIB. Thus, a receiving device may read the bandwidth- dependent information indirectly. For example, in one embodiment the information relating to the bandwidth-dependent information options may be a configuration table which includes one or more information options, each corresponding to one or more respective bandwidth capabilities. Thus, the receiving device may indirectly read the bandwidth-dependent information by locating the entry corresponding to its associated bandwidth capability and then reading from that entry. In another embodiment, the information relating to the one or more bandwidth- dependent information options may be a configuration index that is understood differently by receiving devices with different bandwidth capabilities. T us, the receiving device may indirectly read the bandwidth-dependent information by using the configuration index to reference a predefined configuration table associated with its supported bandwidth. The configuration table of this embodiment may be stored locally in the receiving device, provided by the network 14, or otherwise made available to the receiving device. The different bandwidth capabilities may have the same number of available information options, but this is not required. An example of the content of an SIB-1 according to one embodiment is provided below:

[0038] ScheduIinglnfoList ::= SEQUENCE (SIZE (l..maxSI-Message)) OF Schedulinglnfo

[0039]

[0040] Schedulinglnfo ::= SEQUENCE {

[0041] si-Periodicity ENUMERATED {

[0042] rf , rfl6, rf32, rf64, rfl28, r£256, rf512},

[0043] si-resourceAllocation ENUMERATED {

[0044] ral, ra2, ra3, ...},

[004S] sib-Mappinglnfo SIB-Mappinglnfo

[0046] }

[0047] Continuing to refer to Figure 4, the apparatus 20 may further include means, such as the processing circuitry, the processor 22, the memory 24, the communications interface 26 or the like, for allocating resources for transmitting the SIB, such as an SIB-1, according to a particular allocation scheme. See block 42. For example, the apparatus may allocate physical resource blocks (PRBs) 61 of the PDSCH which carries the SIB according to a particular allocation scheme. For example, in one embodiment the apparatus may allocate resources for transmitting SIB-1 based on a fixed scheme. See block 43a. Referring now to Figure 6, a fixed scheme may involve allocating one or more PRBs 61 that are fixed in the frequency domain. The SIBs may be transmitted within the supported bandwidth of the most bandwidth-limited limited- bandwidth device. Thus, for example, in a system in which the most bandwidth-limited device supports a 1.4MHz bandwidth, it would be advantageous to limit the allocation of one or more PRBs to the central 6 PRBs corresponding to a 1.4MHz bandwidth 3 1 in order to ensure all limited-bandwidth devices could receive the SIB-1. Figure 6 depicts an example in which the central two PRBs in sub frame #5, where System Frame Number (SFN) mod 2 = 0. Any number of other possible fixed schemes will be readily apparent to one of ordinary skill in the art According to another embodiment, the apparatus may allocate resources for transmitting an SIB, such as an SIB-1 , based on a hopping scheme. See block 43b of Figure 4. Referring now to

Figure 7, a hopping scheme may involve allocating one or more PRBs 61 based on a pre-defined hopping pattern. For example, in one embodiment the apparatus 20 may use an input, such as the SFN or Cell index, to determine how to allocate one or more PRBs. For example, Figure 7 depicts a hopping scheme in which the allocated resources are limited to the central six PRBs where the allocated PRB's number (the first of the central 6 PRBs being numbered as 0) = SFN mod 4, and SFN mod 4+2. Any number of other possible hopping schemes will be readily apparent to one of ordinary skill in the art.

[0048] According to another embodiment, the apparatus 20 may allocate resources for transmitting the SIB, such as an SIB-1, based on a blind decoding scheme. In other words, the apparatus may allocate resources in a manner which allows the receiving device, such as a limited-bandwidth device 10, to receive SIB-1 using a blind decoding technique. For example, in one embodiment the apparatus 20 may define a fixed Modulation and Coding Scheme (MCS) and allocate a variable resource length (e.g., a variable number of PRBs), with a limited set of possible resource lengths, for the PDSCH which carries SIB-1 , and let the receiving device use the given MCS to perform blind decoding on the SIB-1. Thus, for example, the size of the SIB may vary from time to time, with additional PRBs being allocated as needed. In another embodiment the apparatus 20 may allocate a fixed resource length and use a limited number of possible MCSs for the PDSCH which carries SIB-1 and let the receiving device use the given resource to perform blind decoding on the SIB-1. In an example embodiment, the MCS may be adjusted to suit the SIB size. For example, if the SIB size is small, a QPSK MCS may be used. If, for example, the SIB size is large, a 16QAM MCS may be used. An identical resource allocation and MCS may be used within a given modification period of the system information in order to reduce complexity. W en a fixed resource and variable MCS is used, the most aggressive MCS option, e.g., the MCS option with the highest coding rate which can carry the most information with the resource, may be chosen to provide sufficient performance taking into consideration the lowest signal to noise ratio (SNR) at the edge of a given cell and after being tran-flmtted/retransmitted four times, e.g., transmitted a first time then retransmitted 3 additional times. It should be understood that allocating resources according to a blind decoding scheme does not preclude the use of a hopping or fixed allocation scheme. Thus, in one embodiment the apparatus 20 may allocate one or more PRBs that are fixed or that hop in the frequency domain and also use a variable resource length (e.g., a variable number of PRBs) along with a fixed MCS. Thus, for example, additional PRBs may be allocated from time to time. The PRBs may, for example, be added based on a pre-defined rule. For example, the pre-defined hopping pattern may provide how additional PRBs are allocated or how previously allocated PRBs are deallocated. Alternatively, the apparatus may allocate one or more PRBs that are fixed or that hop in the frequency domain and use a fixed resource length (e.g., a fixed number of PRBs) along with a variable MCS (e.g., a limited number of possible MCSs). It should further be understood that any suitable allocation scheme may be used according to embodiments of the present invention, besides the fixed, hopping, and blind decoding schemes discussed above.

[0049] Having allocated resources for transmitting the SIB, such as an SIB- 1 , according to a transmission scheme, and continuing to refer to Figure 4, the apparatus 20 may further include means, such as the processing circuitry, the processor 22, the memory 24, the communications interface 26 or the like, for causing the SIB, e.g., SIB-1, to be transmitted using the allocated resources. See block 44.

[0050] The apparatus 20 may further include means, such as the processing circuitry, the processor 22, the memory 24, the communications interface 26 or the like, for preparing one or more subsequent S Bs. See block 46 of Figure 4. As it did with the SIB-1, the apparatus may include bandwidth-independent information and information relating to one or more bandwidth- dependent information options in the subsequent SIBs. See block 41c. Thus, as previously discussed in regards to SIB-1, the receiving device, such as a limited-bandwidth device 10, can directly read the bandwidth-independent information and indirectly read the bandwidth- dependent information. The apparatus 20 may further include means, such as the processing circuitry, the processor 22, the communications interface 26 or the like, for causing one or more subsequent SIBs to be transmitted according to the scheduling information provided in the SIB-1. See block 48.

[005 1] Thus, having described the operations of an apparatus 20 embodied by or otherwise associated with a base station 12, the operations of an apparatus 20 embodied by or otherwise associated with a limited-bandwidth device 10 will now be described. In this regard and referring to Figure S, the apparatus 20 may include means, such as the processing circuitry, the processor 22, the memory 24, the communications interface 26 or the like, for receiving a SIB, e.g., SIB-1. See block SO of Figure 5. The SIB may, for example, be transmitted by the base station 12 as described above. Receiving the SIB may first involve determining what resources have been allocated to the SIB. For example, the apparatus 20 embodied by or otherwise associated with the limited-bandwidth device may use the SFN or Cell index to make this determination. In addition, the apparatus 20 may receive the SIB by performing blind decoding, as discussed above. The SIB may be configured, such as by an apparatus 20 embodied by or otherwise associated with base station 12, to include or otherwise make available to the receiving device 10, data in more than one way, depending on the characteristics of the data. In one embodiment, the SIB may include bandwidth-independent information and information relating to one or more bandwidth-dependent information options.

[0052] With reference to blocks S 1 a and 5 lb, the apparatus 20 associated with limited- bandwidth device 10 may also include means, such as the processor 22, the memory 24, the communications interface 26 or the like, for reading bandwidth-independent information directly from the SIB and reading bandwidth-dependent information indirectly. Thus, in one embodiment, the SIB may be prepared, such as by an apparatus 20 embodied by or otherwise associated with base station 12, so as to contain the bandwidth-independent information in a format which allows the receiving device, such as the limited-bandwidth device 10, to read it directly. See block 51a. The SIB may also be prepared, such as by the apparatus 20 embodied by or otherwise associated with base station 12, to include information related to one or more bandwidth-dependent information options. Thus, the actual bandwidth-dependent information may or may not be contained in the SIB and may be made available in a format that allows the receiving device, such as limited-bandwidth device 10 to read it indirectly. For example, in one embodiment, the apparatus 20 associated with limited-bandwidth device 10 may use a pre-defined configuration table to read the bandwidth-dependent data. Thus, for example, the apparatus 20 associated with the base station 12 may prepare the SIB by including a configuration index in the SIB. The configuration index may be understood differently by different receiving devices 10 based on their bandwidth capabilities. For example, different limited-bandwidth devices 10 may have access to different bandwidth capability-specific configuration tables. Thus, a limited-bandwidth device 10 which supports a given bandwidth may use the configuration index read from the SIB to reference a configuration table associated with the given bandwidth and read corresponding bandwidth-dependent information. The configuration table may be stored on the device 10, provided by the network, or otherwise made available to the device 10. In another embodiment, bandwidth-dependent information for a plurality of different bandwidth capabilities may be contained in the SIB, such as in a configuration table. Thus, a limited-bandwidth device 10 may, for example, indirectly read the bandwidth-dependent information by determining which entry of the configuration table corresponds to the device's supported bandwidth and then reading the corresponding bandwidth-dependent information. It will be understood that many other ways of indirectly reading bandwidth-dependent information are possible and that the method and apparatus are not limited to any one particular embodiment

[0053] The apparatus 20 may further include means, such as the processing circuitry, the processor 22, the memory 24, the communications interface 26 or the like, for reading scheduling information for subsequent SIBs that is included in SIB-1. See block 52. As discussed above, the scheduling included in the SIB-1 may include one or more of the periodicity, frequency resource allocation, time resource allocation and/or a modulation and coding scheme (MCS) for one or more or all of the subsequent SIBs. The MCS may be a single MCS or a plurality of possible MCSs and the SIB-1 may also include E-control channel configuration information that may be read by the apparatus 20 associated with the limited-bandwidth device

10. As with the SIB- 1 , one or more of the subsequent SIBs may also include bandwidth- independent information which the apparatus 20 can read directly and information related to one or more bandwidth-dependent information options, such that the apparatus 20 can indirectly read the bandwidth-dependent information, such as by using a configuration table. See blocks 51 and

51b.

[0054] Embodiments according to the invention may provide many benefits in a system including limited-bandwidth devices. For example, networks, such as LTE networks, may be made accessible to devices with different bandwidth capabilities. Embodiments of the present invention may also save control signaling overhead without the loss of frequency selective SIB scheduling gains associated with transmitting SIBs within the smallest supported bandwidth. Furthermore, embodiments of the present invention may allow SIB sizes to be expanded or reduced as needed or appropriate through the use of flexible resource lengths and blind decoding. [0055] Many modifications and other embodiments of the inventions set forth herein will come to mind to one skilled in the art to which these inventions pertain having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the inventions are not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. Moreover, although the foregoing descriptions and the associated drawings describe example embodiments in the context of certain example combinations of elements and/or functions, it should be appreciated that different combinations of elements and/or functions may be provided by alternative embodiments without departing from the scope of the appended claims. In this regard, for example, different combinations of elements and/or functions than those explicitly described above are also contemplated as may be set forth in some of the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.

Claims

WHAT IS CLAIMED IS:

1. A method comprising:

receiving a system information block (SIB) at a limited-bandwidth device, wherein the SIB comprises bandwidth-independent information and information related to one or more bandwidth-dependent information options;

reading the bandwidth-independent information directly; and

reading bandwidth-dependent information indirectly by using the information related to the one or more bandwidth-dependent information options. 2. The method of claim 1, wherein the information related to the one or more bandwidth-dependent information options comprises a configuration index.

3. The method of claim 2, wherein reading the bandwidth-dependent information using the configuration index comprises using the configuration index to reference a pre-defined configuration table.

4. The method of claim 1 , wherein the information related to the one or more bandwidth-dependent information options comprises a pre-defined configuration table comprising one or more bandwidth-dependent information entries corresponding to one or more respective bandwidth capabilities;

further wherein reading the bandwidth-dependent system information using the predefined configuration table comprises reading the one or more bandwidth-dependent configuration entries that correspond to a bandwidth capability associated with the limited- bandwidth device.

5. The method of any of claims 1 to 4, wherein the SIB is an SIB-1.

6. The method of claim 5, wherein the SIB-1 further comprises scheduling information for one or more subsequent SIBs.

7. The method of claim 6, further comprising using the scheduling information to receive one or more subsequent SIBs.

8. The method of either of claims 6 or 7, wherein the scheduling information comprises one or more of a periodicity, frequency resource allocation, or Modulation and Coding Scheme (MCS).

9. The method of any of claims 5 to 8, wherein the SIB-1 is included within one or more fixed physical resource blocks (PRBs).

10. The method of any of claims S to 8, wherein the SIB-1 is included within one or more PRBs according to a pre-defined hopping pattern.

1 1. The method of any of claims 5 to 10, further comprising determining the one or more PRBs that include the SIB-1 before receiving the SIB-1 based on a system frame number

(SFN) or Cell index.

12. The method of any of claims 5 to 10, wherein receiving the SIB-1 comprises receiving the SIB-1 by performing blind decoding.

13. The method of any of claims 5 to 12, wherein the SIB- 1 is transmitted by using a variable resource length and according to a pre-determined modulation and coding scheme (MCS).

14. The method of any of claims 5 to 12, wherein the SIB-1 is transmitted by using one or more pre-determined PRBs according to one of a limited number of pre-determined MCSs.

15. A method comprising:

preparing a system information block type 1 (SIB-1);

allocating resources for the SIB-1 ; and causing the SIB to be transmitted to a limited-bandwidth device using the allocated resources;

wherein allocating resources for the SIB-1 comprises allocating resources according to either a fixed scheme, a hopping scheme, or a blind decoding scheme.

16. The method of claim IS, wherein allocating resources for the SIB-1 comprises allocating resources according to a fixed scheme by allocating one or more fixed Physical Resource Blocks (PRBs).

17. The method of claim IS, wherein allocating resources for the SIB-1 comprises allocating resources according to a hopping scheme by allocating one or more PRBs according to a pre-defined hopping pattern.

18. The method of claim 1 5, wherein allocating resources for the SIB-1 comprises allocating resources according to a blind decoding scheme by allocating one or more PRBs according to a limited set of possibilities and using a pre-determined modulation and coding scheme (MCS).

1 . The method of claim 1 5, wherein allocating resources for the SIB- 1 comprises allocating resources according to a blind decoding scheme by allocating one or more predetermined PRBs and using one of a limited number of pre-determined MCSs. 20. The method of any of claims IS to 19, wherein preparing the SIB-1 comprises causing E-control channel configuration information to be included in the SIB. 2 1. The method of any of claims 1 5 to 20, wherein preparing the SIB- 1 comprises causing bandwidth-independent information and information relating to one or more bandwidth- dependent information options to be included in the SIB- 1. 22. The method of claim 21, wherein the information relating to the one or more bandwidth-dependent information options comprises a configuration index. 23. The method of claim 21 , wherein the information relating to the one or more bandwidth-dependent information options comprises a pre-defined configuration table. 24. The method of any of claims 1 5 to 23, wherein preparing the SIB- 1 comprises causing scheduling information for one or more subsequent SIBs to be included in the SIB- 1. 25. The method of claim 24, wherein the scheduling information comprises one or more of a periodicity, a frequency resource allocation, or a modulation and coding scheme (MCS). 26. The method of either of claims 24 or 25, further comprising causing the one or more subsequent SIBs to be transmitted according to the scheduling information. 27. The method of any of claims 1 5 to 26, further comprising preparing one or more subsequent SIBs. 28. The method of claim 27, wherein preparing the one or more subsequent SIBs comprises causing bandwidth-independent information and information relating to bandwidth- dependent information options to be included in the one or more subsequent SIBs. 29. The method of any of claims 1 to 28, wherein the limited-bandwidth device comprises a Machine-Type Communications (MTC) device.

30. The method of any of claims 1 to 29, wherein the SIB and/or SIB-1 are transmitted to the limited-bandwidth device by an enhanced Node B (eNB) in a Long Term Evolution (LTE) network. 1. An apparatus comprising at least one processor and at least one memory storing computer program instructions, the at least one memory and computer program instructions being configured to, with the at least one processor, cause the apparatus to at least:

receive a system information block (SIB) at a limited-bandwidth device, wherein the SIB comprises bandwidth-independent information and information related to one or more bandwidth-dependent information options; read the bandwidth-independent information directly; and

read bandwidth-dependent information indirectly by using the information related to the one or more bandwidth-dependent information options. 32. The apparatus of claim 3 1 , wherein the information related to the one or more bandwidth-dependent information options comprises a configuration index.

33. The apparatus of claim 32, wherein the apparatus is caused to read the bandwidth- dependent information using the configuration index by using the configuration index to reference a pre-defined configuration table.

34. The apparatus of claim 3 1 , wherein the information related to the one or more bandwidth-dependent information options comprises a pre-defined configuration table comprising one or more bandwidth-dependent information entries corresponding to one or more respective bandwidth capabilities;

further wherein reading the bandwidth-dependent system information using the predefined configuration table comprises reading the one or more bandwidth-dependent

configuration entries that correspond to a bandwidth capability associated with the limited- bandwidth device.

35. The apparatus of any of claims 3 1 to 34, wherein the SIB is an SIB-1.

36. The apparatus of claim 35, wherein the SIB-1 further comprises scheduling information for one or more subsequent SIBs.

37. The apparatus of claim 36, wherein the apparatus is further caused to use the scheduling information to receive one or more subsequent SIBs.

38. The apparatus of either of claims 36 or 37, wherein the scheduling information comprises one or more of a periodicity, frequency resource allocation, or a Modulation and

Coding Scheme (MCS).

39. The apparatus of any of claims 35 to 38, wherein the SIB-1 is included within one or more fixed physical resource blocks (PRBs).

40. The apparatus of any of claims 35 to 38, wherein the SIB- 1 is included within one or more PRBs according to a pre-defined hopping pattern.

41. The apparatus of any of claims 35 to 40, wherein the apparatus is further caused to determine the one or more PRBs that include the SIB-1 before receiving the SIB-1 based on a system frame number (SFN) or Cell index.

42. The apparatus of any of claims 35 to 40, wherein the apparatus is caused to receive the SIB-1 by performing blind decoding.

43. The apparatus of any of claims 35 to 42, wherein the SIB-1 is transmitted by using a variable resource length and according to a pre-deterrnined modulation and coding scheme (MCS).

44. The apparatus of any of claims 35 to 42, wherein the SIB-1 is transmitted by using one or more pre-determined PRBs according to one of a limited number of pre-deterrnined MCSs.

45. An apparatus comprising at least one processor and at least one memory storing computer program instructions, the at least one memory and computer program instructions being configured to, with the at least one processor, cause the apparatus to at least:

prepare a system information block type 1 (SIB-1);

allocate resources for the SIB- 1; and

cause the SIB-1 to be transmitted to a limited-bandwidth device using the allocated resources;

wherein the apparatus is caused to allocate resources for the SIB-1 according to either a fixed scheme, a hopping scheme, or a blind decoding scheme. 46. The apparatus of claim 45, wherein the apparatus is caused to allocate resources for the SIB-1 according to a fixed scheme by allocating one or more fixed Physical Resource Blocks (PRBs). 47. The apparatus of claim 45, wherein the apparatus is caused to allocate resources for the SIB according to a hopping scheme by allocating one or more PRBs according to a predefined hopping pattern.

48. The apparatus of claim 45, wherein the apparatus is caused to allocate resources for the SIB-1 according to a blind decoding scheme by allocating one or more PRBs according to a limited set of possibilities and using a pre-determined modulation and coding scheme (MCS).

49. The apparatus of claim 45, wherein the apparatus is caused to allocate resources for the SIB-1 according to a blind decoding scheme by allocating one or more pre-determined PRBs and using one of a limited number of pre-detennined MCSs.

50. The apparatus of any of claims 45 to 49, wherein the apparatus is caused to prepare the SIB by causing E-control channel configuration information to be included in the SIB.

5 1. The apparatus of any of claims 45 to 50, wherein the apparatus is caused to prepare the SIB by causing bandwidth-independent information and information relating to one or more bandwidth-dependent information options to be included in the SIB-1.

52. The apparatus of claim 5 1 , wherein the information relating to the one or more bandwidth-dependent information options comprises a configuration index.

53. The apparatus of claim 5 1 , wherein the information relating to the one or more bandwidth-dependent information options comprises a pre-defined configuration table.

54. The apparatus of any of claims 45 to 53, wherein the apparatus is caused to prepare the SIB-1 by causing scheduling information for one or more subsequent SIBs to be included in the SIB-1.

55. The apparatus of claim 54, wherein the scheduling information comprises one or more of a periodicity, a frequency resource allocation, or a modulation and coding scheme (MCS).

56. The apparatus of either of claims 54 or 55, wherein the apparatus is further caused to cause the one or more subsequent SIBs to be transmitted according to the scheduling information.

57. The apparatus of any of claims 45 to 56, wherein the apparatus is further caused to prepare one or more subsequent SIBs.

58. The apparatus of claim 57, wherein the apparatus is caused to prepare the one or more subsequent SIBs by causing bandwidth-independent information and information relating to bandwidth-dependent information options to be included in the one or more subsequent SIBs.

59. The apparatus of any of claims 3 1 to 58, wherein the limited-bandwidth device comprises a Machine-Type Communications (MTC) device.

60. The apparatus of any of claims 3 1 to 59, wherein the SIB and/or SIB- 1 are transmitted to the limited-bandwidth device by an enhanced Node B (eNB) in a Long Term Evolution (LTE) network.

61. A computer program product comprising a computer readable medium storing computer program instructions therein, the computer program instructions being configured to, upon execution, cause an apparatus to at least perform the method according to any of claims 1 to 14.

62. A computer program product comprising a computer readable medium storing computer program instructions therein, the computer program instructions being configured to, upon execution, cause an apparatus to at least perform the method according to any of claims 15