WO2018078658A1

WO2018078658A1 - Method and system for wireless communication between user equipment and base station for narrow-band iot

Info

Publication number: WO2018078658A1
Application number: PCT/IN2017/050502
Authority: WO
Inventors: Kiran Kumar Kuchi; Venkata Siva Santosh GANJI
Original assignee: Wisig Networks Pvt Ltd
Current assignee: Wisig Networks Pvt Ltd
Priority date: 2016-10-28
Filing date: 2017-10-27
Publication date: 2018-05-03
Anticipated expiration: 2019-04-28

Abstract

The present disclosure, generally relates to Narrow band Internet of things (NB-IoT) Time division duplex (TDD) Physical Random Access Channel (PRACH) and Physical Uplink Channel. More particularly relates to sub-frame blanking for NB-IOT uplink by the base station (BS) in communication with the user equipment (UE) coupled with IoT. The base station monitors traffic conditions in the communication network and determine requirement of blanking the resources for PRACH transmission by the UE. Based on the blanking requirement, the BS identifies one or more sub-frames available for blanking and blank the identified sub-frames in at least one Uplink- Downlink (UL-DL) configuration. The BS then broadcasts an output signal comprising information associated with blanking across the communication network, thereby supporting uplink transmission for the seven available UL-DL configurations.

Description

"METHOD AND SYSTEM FOR WIRELESS COMMUNICATION BETWEEN USER EQUIPMENT AND BASE STATION FOR NARROW-BAND IOT"

TECHNICAL FIELD

Embodiments of the present disclosure are related, in general to communication, but exclusively relate to Narrow band Internet of things (NB-IoT) Time division duplex (TDD) Physical Random Access Channel (PRACH) and Physical Uplink Channel.

BACKGROUND

Generally, in all communication schemes, an important prerequisite is to establish the timing synchronization between a receiver and a transmitter. In Long Term Evolution (LTE), the synchronization in downlink is achieved by the special synchronization signals such as primary synchronization signal (PSS) and secondary synchronization signal (SSS). The downlink signals are broadcasted periodically by the Base station (BS). However, in uplink, where the user equipment (UE) is the transmitter and the base station (BS) or Extended NodeB (eNodeB) is the receiver, it is inefficient to transmit periodically special synchronizing signals to establish timing synchronization. Hence, UE transmits physical random access channel to establish timing synchronization and thereby connection establishment with the network. The transmission of a random-access preamble, if triggered by the MAC layer, is restricted to certain time and frequency resources. There are seven different Downlink/Uplink configurations in LTE and the uplink subframes for PRACH transmission are selected based on these configurations.

Narrowband - Internet of Things (NB-IoT) facilitates cellular connectivity for massive number of internet of things. A small chunk of LTE bandwidth has been used and narrow bandwidth has been developed by 3GPP. This provides opportunity to provide connectivity with existing network infrastructure. NB-IoT is being developed considering backward compatibility with LTE network. In NB-IOT PRACH, to initiate communication with network the physical random access channel transmitted by the UE should be received by eNodeB even in low coverage scenario. However, the current implementation does not support any of the 7 available TDD configurations. Therefore, there is a need for a method and system to enable uplink transmission in the available configurations for NB-IOT PRACH. SUMMARY

The shortcomings of the prior art are overcome and additional advantages are provided through the provision of method of the present disclosure. Additional features and advantages are realized through the techniques of the present disclosure. Other embodiments and aspects of the disclosure are described in detail herein and are considered a part of the claimed disclosure.

Accordingly, the present disclosure relates to a method for wireless communication between at least two devices via a communication link, one of the at least two devices is a user equipment (UE) and other of the at least two devices is a base station (BS). The communication link between the user equipment and the base station is uplink (UL), and the communication link between the base station and the user equipment is downlink (DL). The method comprising monitoring a plurality of traffic conditions by the BS in a communication network, wherein the plurality of traffic conditions comprises at least bandwidth requirements, number of connected and unconnected UEs coupled with at least one BS. The method further comprising determining whether or not blanking of time units is required based on the monitored traffic conditions. The time units comprise at least one radio frame and each radio frame comprise one or more sub- frames. Further, the method comprises step of identifying one or more sub-frames available for blanking upon determining and blanking the one or more identified sub-frames in at least one Uplink (UL) - Downlink (DL) configuration. Upon blanking, the BS broadcasts an output signal comprising information associated with the blanking, across the communication network.

Further, the present disclosure relates to a system for wireless communication between at least two devices coupled via a communication link. One of the at least two devices is a user equipment (UE) and other of the at least two devices is a base station (BS) and the communication link between the user equipment and the base station is uplink (UL), and the communication link between the base station and the user equipment is downlink (DL). The base station comprises a processor and a memory communicatively coupled with the processor, configured to store instructions executable by the processor to monitor a plurality of traffic conditions in a communication network. The plurality of traffic conditions comprises at least bandwidth requirements, number of connected and unconnected UEs coupled with at least one BS. The processor is further configured to determine whether or not blanking of time units is required based on the monitored traffic conditions, wherein the time units comprises at least one radio frame and each radio frame comprises one or more sub-frames. Furthermore, the processor identifies one or more sub- frames available for blanking upon determining and blank the one or more identified sub-frames in at least one Uplink (UL) - Downlink (DL) configuration. Upon blanking, the processor broadcasts an output signal comprising information associated with the blanking, across the communication network.

The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

The accompanying drawings, which are incorporated in and constitute a part of this disclosure, illustrate exemplary embodiments and, together with the description, serve to explain the disclosed principles. In the figures, the left-most digit(s) of a reference number identifies the figure in which the reference number first appears. The same numbers are used throughout the figures to reference like features and components. Some embodiments of device or system and/or methods in accordance with embodiments of the present subject matter are now described, by way of example only, and with reference to the accompanying figures, in which:

Figure 1 illustrates an exemplary architecture of a communication environment in accordance with some embodiments of the present disclosure;

Figure 2 is a block diagram of a base station of Figure 1 in accordance with an embodiment of the present disclosure;

Figure 3 illustrates a block diagram conceptually illustrating an example frame structure for a radio access technology for use in wireless communication network in accordance with some embodiments of the present disclosure; and Figure 4 shows a flowchart illustrating a method of wireless communication by a BS for blanking subframes in a Narrow band Internet of things (NB-IoT) Time division duplex (TDD) Physical Random Access Channel (PRACH) communication system, in accordance with an embodiment of the present disclosure.

DETAILED DESCRIPTION

In the present document, the word "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any embodiment or implementation of the present subject matter described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments.

While the disclosure is susceptible to various modifications and alternative forms, specific embodiment thereof has been shown by way of example in the drawings and will be described in detail below. It should be understood, however that it is not intended to limit the disclosure to the particular forms disclosed, but on the contrary, the disclosure is to cover all modifications, equivalents, and alternative falling within the spirit and the scope of the disclosure.

The terms "comprises", "comprising", or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a setup, device or method that comprises a list of components or steps does not include only those components or steps but may include other components or steps not expressly listed or inherent to such setup or device or method. In other words, one or more elements in a device or system or apparatus proceeded by "comprises... a" does not, without more constraints, preclude the existence of other elements or additional elements in the device or system or apparatus.

The terms "an embodiment", "embodiment", "embodiments", "the embodiment", "the embodiments", "one or more embodiments", "some embodiments", and "one embodiment" mean "one or more (but not all) embodiments of the invention(s)" unless expressly specified otherwise. The terms "including", "comprising", "having" and variations thereof mean "including but not limited to", unless expressly specified otherwise. The enumerated listing of items does not imply that any or all of the items are mutually exclusive, unless expressly specified otherwise. The terms "a", "an" and "the" mean "one or more", unless expressly specified otherwise. Random access procedure is an initial procedure required by any user equipment (UE) to establish connection with a cellular network. The purpose of RACH is at least one of achieving uplink link (UL) synchronization between UE and evolved base stations (also referred as eNodeB or eNB), and establishing connection with a network. In LTE-Physical Random Access Channel (PRACH), the PRACH carries a randomly chosen preamble out of 64. Preamble is a CAZAC sequence. The physical layer random access preamble consists of a cyclic prefix of length T_CP and a sequence part of length T_SEQ . The parameter values are listed in Table 1 and depend on the frame structure and the random-access configuration. Higher layers control the preamble format. The below is random access preamble format:

The following is random access preamble parameters:

Table 1

The transmission of a random-access preamble, if triggered by the MAC layer, is restricted to certain time and frequency resources. These resources are enumerated in increasing order of the subframe number within the radio frame and the physical resource blocks in the frequency domain such that index 0 correspond to the lowest numbered physical resource block and subframe within the radio frame. PRACH resources within the radio frame are indicated by a PRACH configuration, which indicates the frame, sub frame, frequency resource, preamble format as per TDD or FDD configuration.

For LTE, time and frequency are divided among users to communication, resources in frequency are called sub- carriers and time is divided in terms of frames, each frame is of 10 msec duration. A frame is divided into sub frame is divided in 10 sub frames, each of 1 msec duration. In the 10 sub-frames, few can be used as uplink transmission resources and few are downlink resources by user equipment. Below table shows already defined uplink, downlink sub frame pattern. Similar pattern can be defined for Narrow band LTE. There are seven different Downlink/Uplink configurations in LTE as shown in the below Table 2:

In PRACH for TDD, resources for the PRACH are configured by eNodeB, which denotes resources in terms of a quadruple. Each quadruple of the format

indicates the location of a specific random access resource, where _RA is a frequency resource index within the considered time instance, rj^ = 0,1,2 indicates whether the resource is reoccurring in all radio frames, in even radio frames, or in odd radio frames, respectively, = 0,1 indicates whether the random access resource is located in first half frame or in second half frame, respectively, and where A i^{s tne} uplink subframe number where the preamble starts, counting from 0 at the first uplink subframe between 2 consecutive downlink-to-uplink switch points. The start of the random- access preamble formats shall be aligned with the start of the corresponding uplink subframe at the UE. There are seven different Downlink/Uplink configurations in LTE. The uplink subframes for PRACH are selected based on the configuration.

NB-IoT is to facilitate cellular connectivity for massive number of internet of things. A small chunk of LTE bandwidth ( 180KHz) has been taken and narrow bandwidth has been developed by 3GPP. This provides opportunity to provide connectivity with existing network infrastructure. NB- IoT is being developed keeping in mind backward compatibility with LTE network, the NB-IoT can be deployed in 3 different modes to cater wide variety of use cases:

1. In-Band mode: Deployed within existing LTE band

2. Guard Band mode: Deployed within guard band of existing LTE

3. Standalone mode: making use of low bandwidth lone carrier

An architecture of NB-IoT may be adopted much from LTE - 3rd Generation Partnership Project (3GPP) standards, also referred as LTE-3GPP standards and modified based on the requirements. A NB- IoT modem have the advantages such as wide area ubiquitous coverage, fast upgrade of existing network, low-power consumption guaranteeing ten years' battery life, high coupling, low cost terminal, plug and play, high reliability and high carrier-class network security.

In NB-IOT PRACH, to initiate communication with network the physical random access channel transmitted by a UE should be received by eNodeB even in low coverage scenario. Existing NB-IoT standard defines following format called N-PRACH for FDD with 3.75KHz sub carrier spacing. The physical layer random access preamble is based on single-subcarrier frequency-hopping symbol groups. Fig. 1 shows an illustration of a symbol group, consisting of a cyclic prefix of length T_CP and a sequence of 5 identical symbols with total length r_SEQ . The parameter values of random access preamble are listed in the below Table 3 :

Table 3

The preamble consisting of 4 symbol groups transmitted without gaps shall be transmitted ^re ^RACH times. The transmission of a random-access preamble, if triggered by the MAC layer, is restricted to certain time and frequency resources. For FDD, the NPRACH do not have a cap on time domain resources. With 3.75KHz spacing total duration for single repetition of PRACH is 6.4msecs which is little more than 7 LTE -TDD sub-frames. As disclosed in the present disclosure, the BS determines sub-frame blanking for NB-IOT uplink and indicate the same to the user equipment (UE) coupled with IoT for PRACH transmission. The base station monitors traffic conditions in the communication network and determine requirement of blanking the resources for PRACH transmission by the UE. Based on the blanking requirement, the BS identifies one or more sub-frames available for blanking and blank the identified sub-frames in at least one Uplink-Downlink (UL-DL) configuration. The BS then broadcasts an output signal comprising information associated with blanking across the communication network, thereby supporting uplink transmission for the seven available UL-DL configurations.

In the following detailed description of the embodiments of the disclosure, reference is made to the accompanying drawings that form a part hereof, and in which are shown by way of illustration specific embodiments in which the disclosure may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the disclosure, and it is to be understood that other embodiments may be utilized and that changes may be made without departing from the scope of the present disclosure. The following description is, therefore, not to be taken in a limiting sense.

The term "IoT" is used herein to refer to a wireless device that may use radio frequency (RF) communications to communicate with another device (or user), for example, as a participant in a communication network, such as the IoT. Such communications may include communications with another wireless device, a base station (including a cellular communication network base station and an IoT base station), an access point (including an IoT access point), or other wireless devices.

A device implementing various embodiments may include any one or all of cellular telephones, smart phones, personal or mobile multi-media players, personal data assistants (PDAs), laptop computers, tablet computers, smart books, palmtop computers, gaming systems and controllers, smart appliances including televisions, set top boxes, kitchen appliances, lights and lighting systems, smart electricity meters, air conditioning/HVAC systems, thermostats, building security systems including door and window locks, vehicular entertainment systems, vehicular diagnostic and monitoring systems, unmanned and/or semi-autonomous aerial vehicles, automobiles, sensors, machine-to-machine devices, and similar devices that include a programmable processor and memory and circuitry for establishing wireless communication pathways and transmitting/receiving data via wireless communication pathways.

The term "component" is intended to include a computer-related part, functionality or entity, such as, but not limited to, hardware, firmware, a combination of hardware and software, software, or software in execution, that is configured to perform particular operations or functions. For example, a component may be, but is not limited to, a process running on a processor, a processor, an object, an executable, a thread of execution, a program, and/or a computer. By way of illustration, both an application running on a computing device and the computing device may be referred to as a component. One or more components may reside within a process and/or thread of execution and a component may be localized on one processor or core and/or distributed between two or more processors or cores. In addition, these components may execute from various non-transitory computer readable media having various instructions and/or data structures stored thereon. Components may communicate by way of local and/or remote processes, function or procedure calls, electronic signals, data packets, memory read/writes, and other known computer, processor, and/or process related communication methodologies.

Figure 1 illustrates a block diagram of exemplary architecture of a communication environment 100 in accordance with some embodiments of the present disclosure.

As illustrated in Fig. l, the system 100 comprises a plurality of user equipment 102-1, 102-2, .. 102-N (collectively referred to as UE 102), and a plurality of base stations 104-1, 104-2, .. 104- N (collectively referred to as BS 104) coupled via a communication network 106. The system 100 further comprises one or more connected devices 108-1, 108-2, .. ,108-N (collectively referred to as connected devices 108) coupled with the UE 102.

The BS 104 may include a cellular network base station, which may support communications for a variety of other wireless communication devices. Such wireless communication devices may include UE 102, which may communicate with the BS 104 over the communication link 106. Such wireless communication devices may also include small cells or a wireless access points (not shown), which may include a micro cell, a femto cell, a pico cell, a Wi-Fi access point, and other similar network access points. The UE 102 and wireless access points may communicate with the base station over the wireless communication link 106.

The wireless communication links among the connected devices (alternatively referred to as IoE or IoT) 108 and between the IoE devices and the BS 104 may include a plurality of carrier signals, frequencies, or frequency bands, each of which may include a plurality of logical channels. Each of the wireless communication links may utilize one or more radio access technologies (RATs). Examples of RATs that may be used in one or more of the various wireless communication links within the communication environment 100 include 3GPP Long Term Evolution (LTE), 3G, 4G, 5G, Global System for Mobility (GSM), Code Division Multiple Access (CDMA), Wideband Code Division Multiple Access (WCDMA), Worldwide Interoperability for Microwave Access (WiMAX), Time Division Multiple Access (TDMA), and other mobile telephony communication technologies cellular RATs. Further examples of RATs that may be used in one or more of the various wireless communication links within the communication environment 100 include medium range protocols such as Wi-Fi, LTE-U, LTE-Direct, LAA, MuLTEfire, and relatively short range RATs such as Wi-Fi, ZigBee, Bluetooth, and Bluetooth Low Energy (LE). In some embodiments, some of the communication links may use an IoE communication protocol. An IoE communication protocol may include LTE Machine-Type Communication (LTE MTC), Narrow Band LTE (NB-LTE), Cellular IoT (CIoT), Narrow Band IoT (NB-IoT), BT Smart, Bluetooth Low Energy (BT-LE), Institute of Electrical and Electronics Engineers (IEEE) 802.15.4, and extended range wide area physical layer interfaces (PHYs) such as Random Phase Multiple Access (RPMA), Ultra Narrow Band (UNB), Low Power Long Range (LoRa), Low Power Long Range Wide Area Network (LoRaWAN), and Weightless.

The IoE devices 108 may be built into a variety of devices, including wireless access points supporting local wireless networks and smart appliances communicating with wireless networks. Non-limiting examples of smart appliances include televisions, set top boxes, kitchen appliances, lights and lighting systems, smart electricity meters, air conditioning/HVAC systems, thermostats, building security systems, doors and windows, door and window locks, and building diagnostic and monitoring systems. An IoE device 108 may also be in communication with, or coupled to, a system, device, or structure. Non-limiting examples of systems that may implement IoE devices 108 include a lighting system, connected cars, one or more components or elements in a factory, a smart meter or power monitoring system, and a residential or commercial security system.

The UE 102, may be referred to as access terminal, mobile station, and a subscriber unit. The UE 102 may be a cellular phone, a personal digital assistant (PDA), a wireless modem, a handheld device, a wireless communication device, a tablet, a smart phone, a notebook etc. The UE 102 includes at least one processor, such as a general processor, which may be coupled to at least one memory. The memory may be a non-transitory computer-readable storage medium that stores processor-executable instructions. The memory may store an operating system, user application software, and/or other executable instructions. The memory may also store application data, such as an array data structure. The memory may include one or more caches, read only memory (ROM), random access memory (RAM), electrically erasable programmable ROM (EEPROM), static RAM (SRAM), dynamic RAM (DRAM), or other types of memory. The general processor may read and write information to and from the memory. The memory may also store instructions associated with one or more protocol stacks. A protocol stack generally includes computer executable instructions to enable communication using a radio access protocol or communication protocol.

The processor and the memory may perform modem functions for communications with one or more other IoE devices, access points, base stations, and other such devices. In some embodiments, the processor may also communicate with a physical interface configured to enable a wired connection to another device. The physical interface may include one or more input/output (I/O) ports configured to enable communications with the device to which the UE 102 device is connected. The physical interface may also include one or more sensors to enable the UE 102 to detect information about a device with which the UE 102 is connected via the physical interface. Examples of devices with which the UE 102 may be connected include smart appliances including televisions, set top boxes, kitchen appliances, lights and lighting systems, smart electricity meters, air conditioning/HVAC systems, thermostats, building security systems, doors and windows, door and window locks, building diagnostic and monitoring systems, and other devices. The BS 104 may be a typical base station, as illustrated in Figure 2. The BS 104 comprises at least a processor 202, and a memory 204 coupled with the processor 202. The processor 202 may be configured to perform one or more functions of the BS 104 for blanking the one or more sub-frames for uplink transmission. In addition, the processor 202 may also generate reference symbols for reference signals, such as for example, common reference signals (CRS), and synchronization signals (primary and secondary synchronization signals). The processor 202 also performs spatial processing on the data symbols, the control symbols and the reference symbols and provides output symbol stream to one or more modulators (not shown). The modulators convert the output symbol stream to obtain a downlink signal that may transmitted via at least one antenna of the BS 104. The BS 104 may also comprise modules 206 for performing various operations in accordance with the embodiments of the present disclosure.

The modules 206 includes a traffic monitoring module 208, a blanking module 210, and a broadcasting module 212. The modules 206 also comprises other modules 214 to perform various miscellaneous functionalities of the BS 104. It will be appreciated that such aforementioned modules may be represented as a single module or a combination of different modules. The modules 206 may be implemented in the form of software executed by a processor, hardware and/or firmware.

In operation, the system enables the communication between the UE 102 and the BS 104, in a narrow band (NB) internet of things (IoT) Time division duplex (TDD) communication. To enable the communication, the UE 102 transmits PRACH preamble for timing synchronization with the BS 104 and establishing connection with the communication network 106. The PRACH preamble is generated by the BS 104 based on the traffic conditions. In one embodiment, the traffic monitoring module 208 of the BS 104 monitors a plurality of traffic conditions including such as bandwidth requirements, information about one or more connected and unconnected UEs 102 coupled with the BS 104 and other related information. Based on the monitored traffic conditions, the BS 104 determines as to whether blanking of resources is required or not.

In one embodiment, the blanking module 210 determines whether or not blanking of resources is required to enable the uplink transmission. In one example, resources may include time units of radio frame i.e., each time unit comprises at least one radio frame 304-1, 304-2, ... 304-N (collectively referred to as radio frame 304) and each radio frame comprise one or more sub-frames 306-1, 306-2, ...302-10 as illustrated in Figure 3. Each radio frame may have a predetermined time duration for example, 10 milliseconds (ms) and may be partitioned into 10 subframes with indices of 0 through 9. The blanking module 210 determines the requirement of blanking of resources or sub-frames for uplink transmission. In one embodiment, the blanking module 210 identifies the number of UEs 102 available in the communication network 106 that requires uplink transmission and calculates the number of connected devices 108 coupled with the identified number of UEs 102. Based on comparison of the number of UEs 102 and connected devices 108, the blanking module 210 determines the requirement of blanking.

For example, if the number of available UEs 102 that require uplink transmission is lesser than the number of connected devices 108, then the blanking module 210 determines that the blanking is required. In another example, if the number of available UEs 102 that require uplink transmission is more than the number of connected devices 108, then the blanking module 210 determines that the blanking is not required. Upon determining that the blanking is required, the BS 104 identifies the one or more sub-frames for blanking.

In one embodiment, the blanking module 210 estimates the number of sub-frames required for uplink transmission and number of available sub-frames for the UL-DL configuration. In one example, the sub-frames required for uplink transmission is denoted by 'U' and the sub-frames required for downlink transmission is denoted by 'D' in the UL-DL configuration. The blanking module 210 identifies the number of sub-frames to be blanked based on comparison of estimated number of sub-frames and the number of available sub-frames for the UL-DL configuration. In one embodiment, if the blanking module 210 determines that the estimated number of sub-frames exceeds the number of available sub-frames for the UL-DL configuration, then the number of sub- frames that are more than the available sub-frames are identified for blanking. The blanking module 210 blanks the one or more identified sub frames in various UL/DL configurations to allow repetition of PRACH symbols thereby enabling transmission of longer duration PRACH channel. The blanking of subframes may be made as per sub carrier duration as PRACH/PUSCH duration is dependent on it. So, the blanking is performed as per symbol repetitions required for PRACH/PUSCH transmission. The symbol duration for different sub carrier spacing are compared and accordingly number of sub- frames to be blanked are decided.

Tsl.25 = 1 -5Ts3.75 = 6Tsl5

The blanking module 210 determines the periodicity of blanking the one or more identified sub-frames within at least one radio frame based on the type of UL-DL configuration. The UL- DL configuration comprises at least one pattern of sub-frames, wherein each sub-frame is available for one of downlink, uplink transmission and both uplink-downlink transmissions.

After blanking sub-frames following is the possible configuration, as shown in Table-4.

Table 4

As shown in Table 4, the one or more subframes blanked are denoted as 'B' to indicate the UEs 102 to transmit PRACH over those subframes. As illustrated in Table 4, there are multiple combinations possible in blanking the sub-frames. In one embodiment, the sub frame blanking is performed periodically so as not to impact cell capacity of much. Also, sub frame blanking is performed at times where network load is minimal and during other network conditions. This method of communication by blanking the sub-frames in at least one uplink sub-carrier frequency selected as one or more of 1.25KHz,3.75KHz, 5KHz, 7.5KHz and 15KHz. One or more sub carriers are allotted for each UE and accordingly blanking pattern is achieved. In one embodiment, the blanking module 210 determines at least one pattern of blanking of the one or more sub-frames based on uplink sub-carrier frequency, uplink duration and periodicity. Periodicity refers to number of repetitions chosen.

In one embodiment, multiple repetitions of PRACH symbols are performed to support all possible coverage classes. To boost receiver signal to noise ratio (SNR) for transmitted PRACH/PUSCH symbols, repetitions are allowed. Based on symbol duration and repetitions chosen, blanking pattern is to be changed. The below Table-5 shows another illustration, in which K denotes the periodicity of PRACH symbol group.

The broadcasting module 212 broadcasts an output signal comprising information associated with the blanking, across the communication network to enable the UE 102 to transmit PRACH preamble for timing synchronization with the BS 104 and thereby establishing connection with the communication network 106.

Fig. 4 shows a flowchart illustrating a method of wireless communication by a BS for blanking subframes in a Narrow band Internet of things (NB-IoT) Time division duplex (TDD) Physical Random Access Channel (PRACH) communication system in accordance with some embodiments of the present disclosure. As illustrated in Figure 4, the method 400 comprises one or more blocks implemented by the processor 202 for blanking sub-frames in uplink transmission. The method 400 may be described in the general context of computer executable instructions. The order in which the method 400 is described is not intended to be construed as a limitation, and any number of the described method blocks can be combined in any order to implement the method. Additionally, individual blocks may be deleted from the methods without departing from the spirit and scope of the subject matter described herein. Furthermore, the method can be implemented in any suitable hardware, software, firmware, or combination thereof.

At block 402, traffic conditions are monitored. In one embodiment, the traffic monitoring module 208 of the BS 104 monitors a plurality of traffic conditions including such as bandwidth requirements, information about one or more connected and unconnected UEs 102 coupled with the BS 104 and other related information. Based on the monitored traffic conditions, the BS 104 determines as to whether blanking of resources is required or not.

At block 404, blanking requirement is decided. In one embodiment, the blanking module 210 determines whether or not blanking of resources is required to enable the uplink transmission. The blanking module 210 determines the requirement of blanking of resources or sub-frames for uplink transmission. In one embodiment, the blanking module 210 identifies the number of UEs 102 available in the communication network 106 that requires uplink transmission and calculates the number of connected devices 108 coupled with the identified number of UEs 102. Based on comparison of the number of UEs 102 and connected devices 108, the blanking module 210 determines the requirement of blanking.

For example, if the number of available UEs 102 that require uplink transmission is lesser than the number of connected devices 108, then the blanking module 210 determines that the blanking is required. In another example, if the number of available UEs 102 that require uplink transmission is more than the number of connected devices 108, then the blanking module 210 determines that the blanking is not required. Upon determining that the blanking is required, the BS 104 identifies the one or more sub-frames for blanking. At block 406, sub-frames for blanking are identified. In one embodiment, the blanking module 210 estimates the number of sub-frames required for uplink transmission and number of available sub- frames for the UL-DL configuration. The blanking module 210 identifies the number of sub-frames to be blanked based on comparison of estimated number of sub-frames and the number of available sub- frames for the UL-DL configuration. In one embodiment, if the blanking module 210 determines that the estimated number of sub-frames exceeds the number of available sub-frames for the UL-DL configuration, then the number of sub-frames that are more than the available sub- frames are identified for blanking.

At block 408, identified sub-frames are blanked. The blanking module 210 blanks the one or more identified sub frames in various UL/DL configurations to allow repetition of PRACH symbols thereby enabling transmission of longer duration PRACH channel. One or more sub carriers are allotted for each UE and accordingly blanking pattern is achieved. In one embodiment, the blanking module 210 determines at least one pattern of blanking of the one or more sub-frames based on uplink sub-carrier frequency, uplink duration and periodicity.

At block 410, output signal is broadcasted. The broadcasting module 212 broadcasts an output signal comprising information associated with the blanking, across the communication network to enable the UE 102 to transmit PRACH preamble for timing synchronization with the BS 104 and thereby establishing connection with the communication network 106.

The described operations may be implemented as a method, system or article of manufacture using standard programming and/or engineering techniques to produce software, firmware, hardware, or any combination thereof. The described operations may be implemented as code maintained in a "non-transitory computer readable medium", where a processor may read and execute the code from the computer readable medium. The processor is at least one of a microprocessor and a processor capable of processing and executing the queries. A non-transitory computer readable medium may comprise media such as magnetic storage medium (e.g., hard disk drives, floppy disks, tape, etc.), optical storage (CD-ROMs, DVDs, optical disks, etc.), volatile and non- volatile memory devices (e.g., EEPROMs, ROMs, PROMs, RAMs, DRAMs, SRAMs, Flash Memory, firmware, programmable logic, etc.), etc. Further, non-transitory computer- readable media comprise all computer-readable media except for a transitory. The code implementing the described operations may further be implemented in hardware logic (e.g., an integrated circuit chip, Programmable Gate Array (PGA), Application Specific Integrated Circuit (ASIC), etc.).

Still further, the code implementing the described operations may be implemented in "transmission signals", where transmission signals may propagate through space or through a transmission media, such as an optical fiber, copper wire, etc. The transmission signals in which the code or logic is encoded may further comprise a wireless signal, satellite transmission, radio waves, infrared signals, Bluetooth, etc. The transmission signals in which the code or logic is encoded is capable of being transmitted by a transmitting station and received by a receiving station, where the code or logic encoded in the transmission signal may be decoded and stored in hardware or a non-transitory computer readable medium at the receiving and transmitting stations or devices. An "article of manufacture" comprises non-transitory computer readable medium, hardware logic, and/or transmission signals in which code may be implemented. A device in which the code implementing the described embodiments of operations is encoded may comprise a computer readable medium or hardware logic. Of course, those skilled in the art will recognize that many modifications may be made to this configuration without departing from the scope of the invention, and that the article of manufacture may comprise suitable information bearing medium known in the art.

A description of an embodiment with several components in communication with each other does not imply that all such components are required. On the contrary a variety of optional components are described to illustrate the wide variety of possible embodiments of the invention.

When a single device or article is described herein, it will be clear that more than one device/article (whether they cooperate) may be used in place of a single device/article. Similarly, where more than one device or article is described herein (whether they cooperate), it will be clear that a single device/article may be used in place of the more than one device or article or a different number of devices/articles may be used instead of the shown number of devices or programs. The functionality and/or the features of a device may be alternatively embodied by one or more other devices which are not explicitly described as having such functionality/features. Thus, other embodiments of the invention need not include the device itself.

Finally, the language used in the specification has been principally selected for readability and instructional purposes, and it may not have been selected to delineate or circumscribe the inventive subject matter. It is therefore intended that the scope of the invention be limited not by this detailed description. Accordingly, the disclosure of the embodiments of the invention is intended to be illustrative, but not limiting, of the scope of the invention.

While various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting.

Claims

The Claim:

1. A method for wireless communication between at least two devices via a communication link, one of the at least two devices is a user equipment (UE) and other of the at least two devices is a base station (BS) and the communication link between the user equipment and the base station is uplink (UL), and the communication link between the base station and the user equipment is downlink (DL), method comprising:

monitoring, by a processor of BS, a plurality of traffic conditions in a communication network, wherein the plurality of traffic conditions comprises at least bandwidth requirements, number of connected and unconnected UEs coupled with at least one BS; determining, by the processor, whether blanking of time units is required based on the monitored traffic conditions, wherein the time units comprises one or more sub- frames; identifying, by the processor, one or more sub-frames available for blanking upon determining;

blanking, by the processor, the one or more identified sub-frames in at least one Uplink (UL) - Downlink (DL) configuration; and

broadcasting, by the processor, an output signal comprising information associated with the blanking, across the communication network.

2. The method as claimed in claim 1 , wherein the step of determination of whether blanking of resources is required comprises one or more steps of:

identifying number of UEs available in the communication network that requires uplink transmission;

calculating number of connected devices coupled with the identified number of UEs; and

determining whether the blanking of resources is required or not based on comparison of the number of UEs and the number of connected devices.

3. The method as claimed in claim 1 , wherein the step of identifying the number of sub-frames for blanking is performed by:

estimating number of sub- frames required for uplink transmission; determining as to whether the estimated number of sub- frames exceeds the number of available sub-frames for the UL-DL configuration; and

identifying the number of sub-frames to be blanked based on determination.

4. The method as claimed in claim 1, wherein the blanking of the one or more sub-frames comprises steps of:

determining periodicity of blanking the one or more sub-frames within at least one radio frame based on the type of UL-DL configuration, wherein the periodicity refers to number of repetitions chosen; and

determining at least one pattern of blanking of the one or more sub-frames based on uplink sub-carrier frequency, uplink duration and periodicity.

5. The method as claimed in claim 1, wherein the blanking of subframes is supported in at least one uplink sub-carrier frequency selected as one or more of 1.25KHz, 3.75 KHz, 5KHz,7.5KHz, and 15KHz.

6. The method as claimed in claim 1, wherein the broadcasted blanking information comprises blanking condition, at least one blanking pattern and periodicity.

7. The method as claimed in claim 1, wherein the step of blanking of DL sub-frames is performed at time intervals so as not to impact cell capacity.

8. The method as claimed in claim 1, wherein the step of blanking of DL sub-frames is performed during at least minimal network load condition and other related network conditions.

9. The method as claimed in claim 1, wherein the UL- DL configuration comprises at least one pattern of sub-frames, wherein each sub- frame is available for one of downlink, uplink transmission and both uplink-downlink transmissions.

10. A system for wireless communication, comprising:

at least two devices coupled via a communication link, wherein one of the at least two devices is a user equipment (UE) and other of the at least two devices is a base station (BS) and the communication link between the user equipment and the base station is uplink (UL), and the communication link between the base station and the user equipment is downlink (DL);

wherein the base station comprises a processor and a memory communicatively coupled with the processor, configured to store instructions executable by the processor to:

monitor a plurality of traffic conditions in a communication network, wherein the plurality of traffic conditions comprises at least bandwidth requirements, number of connected and unconnected UEs coupled with at least one BS;

determine whether blanking of time units is required based on the monitored traffic conditions, wherein the time units comprises one or more sub- frames;

identify one or more sub- frames available for blanking upon determining; blank the one or more identified sub-frames in at least one Uplink (UL) - Downlink (DL) configuration; and

broadcast an output signal comprising information associated with the blanking, across the communication network.

11. The system as claimed in claim 10, wherein the processor is configured to determine whether blanking of resources is required by performing one or more steps of:

12. The system as claimed in claim 10, wherein the processor identifies the number of sub- frames for blanking by:

estimating number of sub- frames required for uplink transmission;

determining as to whether the estimated number of sub- frames exceeds the number of available sub-frames for the UL-DL configuration; and identifying the number of sub-frames to be blanked based on determination.

13. The system as claimed in claim 10, wherein the processor is configured to perform blanking of the one or more sub-frames by steps of:

determining at least one pattern of blanking of the one or more sub- frames based on uplink sub-carrier frequency, uplink duration and periodicity.

14. The system as claimed in claim 10, wherein the blanking of subframes is supported in at least one uplink sub-carrier frequency selected as one or more of 1.25KHz, 3.75 KHz, 5KHz,7.5KHz, and 15KHz.

15. The system as claimed in claim 10, wherein the broadcasted blanking information comprises blanking condition, at least one blanking pattern and periodicity.

16. The system as claimed in claim 10, wherein the processor is configured to blank DL sub- frames at time intervals so as not to impact cell capacity.

17. The system as claimed in claim 10, wherein the processor is configured to blank DL sub- frames during at least minimal network load condition and other related network conditions.

18. The system as claimed in claim 10, wherein the UL- DL configuration comprises at least one pattern of sub-frames, wherein each sub- frame is available for one of downlink, uplink transmission and both uplink-downlink transmissions.