WO2015035597A1

WO2015035597A1 - Apparatus and method for communication

Info

Publication number: WO2015035597A1
Application number: PCT/CN2013/083443
Authority: WO
Inventors: Li Zhang; Peter Skov
Original assignee: Nokia Siemens Networks Oy
Priority date: 2013-09-13
Filing date: 2013-09-13
Publication date: 2015-03-19

Abstract

Apparatuses and methods for communication are provided. The solution comprises controlling (202) the transmission of a random access message to an access point on a physical random access channel without access point- specific configuration; controlling (204) the reception of a response to the random access message on physical downlink shared channel without downlink control information from physical downlink control channels; and obtaining (206) one or more access point-specific configurations and determining resources for uplink transmission utilizing the response.

Description

APPARATUS AND METHOD FOR COMMUNICATION

Field

The exemplary and non-limiting embodiments of the invention relate generally to wireless communication systems. Background

The following description of background art may include insights, discoveries, understandings or disclosures, or associations together with disclosures not known to the relevant art prior to the present invention but provided by the invention. Some of such contributions of the invention may be specifically pointed out below, whereas other such contributions of the invention will be apparent from their context.

Wireless communication systems are constantly under development. Developing systems provide a cost-effective support of high data rates and efficient resource utilization. One communication system under development is the 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE). An improved version of the Long Term Evolution radio access system is called LTE-Advanced (LTE-A). The LTE is designed to support various services, such as high-speed data, multimedia unicast and multimedia broadcast services.

In the development of wireless communication systems a trend towards user equipment (UE) specific operation has been considered. An evolution trend is to have less cell-specific operation, e.g. removal of common reference signals (CRS) and minimize the transmission of cell-specific information and corresponding control channels.

Summary

The following presents a simplified summary of the invention in order to provide a basic understanding of some aspects of the invention. This summary is not an extensive overview of the invention. It is not intended to identify key/critical elements of the invention or to delineate the scope of the invention. Its sole purpose is to present some concepts of the invention in a simplified form as a prelude to a more detailed description that is presented later. According to an aspect of the present invention, there is provided an apparatus in a communication system, comprising: at least one processor; and at least one memory including computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to perform: control the transmission of a random access message to an access point on a physical random access channel without access point-specific configuration; control the reception of a response to the random access message on physical downlink shared channel without downlink control information from physical downlink control channels; and obtain one or more access point-specific configurations and determine resources for uplink transmission utilizing the response.

According to an aspect of the present invention, there is provided an apparatus in a communication system, comprising: at least one processor; and at least one memory including computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to perform: control the reception of a random access message from user equipment on a physical random access channel; control the transmission of a response on physical downlink shared channel without downlink control information from physical downlink control channels.

According to another aspect of the present invention, there is provided a method in a communication system, comprising: controlling the transmission of a random access message to an access point on a physical random access channel without access point-specific configuration; controlling the reception of a response to the random access message on physical downlink shared channel without downlink control information from physical downlink control channels; and obtaining one or more access point-specific configurations and determining resources for uplink transmission utilizing the response.

According to another aspect of the present invention, there is provided a method in a communication system, comprising: controlling the reception of a random access message from user equipment on a physical random access channel; and controlling the transmission of a response on physical downlink shared channel without downlink control information from physical downlink control channels. List of drawings

Embodiments of the present invention are described below, by way of example only, with reference to the accompanying drawings, in which

Figure 1 illustrates an example of a communication environment;

Figures 2 and 3 are flowcharts illustrating embodiments of the invention;

Figures 4A and 4B illustrate examples of apparatuses applying embodiments of the invention. Description of some embodiments

Some embodiments of the present invention are applicable to user equipment (UE), a base station, eNodeB, a corresponding component, and/or to any communication system or any combination of different communication systems that support required functionality.

The protocols used, the specifications of communication systems, servers and user equipment, especially in wireless communication, develop rapidly. Such development may require extra changes to an embodiment. Therefore, all words and expressions should be interpreted broadly and they are intended to illustrate, not to restrict, embodiments.

Many different radio protocols to be used in communications systems exist. Some examples of different communication systems are the universal mobile telecommunications system (UMTS) radio access network (UTRAN), HSPA (High Speed Packet Access), long term evolution (LTE®, known also as evolved UMTS Terrestrial Radio Access Network E-UTRAN), long term evolution advanced (LTE-A), Wireless Local Area Network (WLAN) based on IEEE 802.1 I stardard, worldwide interoperability for microwave access (WiMAX®), Bluetooth®, personal communications services (PCS) and systems using ultra-wideband (UWB) technology. IEEE refers to the Institute of Electrical and Electronics Engineers. For example, LTE® and LTE-A are developed by the Third Generation Partnership Project 3GPP.

Figure 1 illustrates a simplified view of a communication environment only showing some elements and functional entities, all being logical units whose implementation may differ from what is shown. The connections shown in Figure 1 are logical connections; the actual physical connections may be different. It is apparent to a person skilled in the art that the systems also comprise other functions and structures. It should be appreciated that the functions, structures, elements and the protocols used in or for communication are irrelevant to the actual invention. Therefore, they need not to be discussed in more detail here.

In the example of Figure 1 , a radio system based on LTE/SAE

(Long Term Evolution/System Architecture Evolution) network elements is shown. However, the embodiments described in these examples are not limited to the LTE/SAE radio systems but can also be implemented in other radio systems.

The simplified example of a network of Figure 1 comprises a SAE

Gateway 110 and an MME 1 12. The SAE Gateway 1 10 provides a connection to Internet 1 14. Figure 1 shows a base station or an eNodeB 102 serving a cell 100. In this example, the eNodeB 102 is connected to the SAE Gateway 1 10 and the MME 1 12.

The eNodeBs (Enhanced node Bs) of a communication system may host the functions for Radio Resource Management: Radio Bearer Control, Radio Admission Control, Connection Mobility Control, Dynamic Resource Allocation (scheduling). The MME 1 12 (Mobility Management Entity) is responsible for the overall UE control in mobility, session/call and state management with assistance of the eNodeBs through which the UEs connect to the network. The SAE GW 1 10 is an entity configured to act as a gateway between the network and other parts of communication network such as the Internet for example. The SAE GW may be a combination of two gateways, a serving gateway (S-GW) and a packet data network gateway (P-GW).

The eNodeB 102 may provide radio coverage to a cell 100. The cell

100 may be a macrocell, a microcell, or any other type of cell where radio coverage is present. Further, the cell 100 may be of any size or form, depending on the antenna system utilized. The eNodeB 102 may be used in order to provide radio coverage to the cell 100. The eNodeB 102 may control a cellular radio communication link established between the eNodeB 102 and terminal devices or user equipment 104A and 104B located within the cell 100. These communication links marked with solid arrows may be referred as conventional communication links for end-to-end communication, where the source device transmits data to the destination device via the base station 100. Therefore, the user equipment 104A and 104B may communicate with each other via the base station 102. The user equipment may be a user equipment of a cellular communication system, e.g. a computer (PC), a laptop, a handheld computer, a mobile phone, or any other user terminal or user equipment capable of communicating with the cellular communication network.

In addition to or instead of the conventional communication links, direct device-to-device (D2D) connections may be established among terminal devices. Direct communication links between two devices may be established, e.g., between terminal devices or user equipment 106 and 108 in Figure 1 . A direct communication link 1 16 marked with a dashed arrow may be based on any radio technology such that the terminal devices or user equipment 106 and 108 involved in the direct communication may apply communication according to any of a plurality of radio access technologies. The eNodeB 102 may be responsible for controlling the direct communication link 1 16, as shown with dotted, bi-directional lines 1 18 in Figure 1 . The radio access technology of the direct communication link 1 16 may operate on the same frequency band as the conventional communication link and/or outside those frequency bands to provide the arrangement with flexibility. Thus, the eNodeB 102 may be responsible for allocating radio resources to the direct communication link 1 16 as well as for the conventional communication links. Alternatively, the UT 106, 108 may perform auto-selection of D2D resources from a common pool of resources.

Generally, in present systems the eNodeBs send system information (SI) to the user equipment in their area. However, in recent studies local area optimization and D2D communication have been emphasised. In those scenarios it may not make sense for an access point (AP) or eNodeB to always broadcast some common information (e.g. SI in current LTE), since there would not be many UEs served by the AP, and any configuration change can be signalled in a UE-specific manner.

However, reducing the common information transmitted by an access point or eNodeB For example in current LTE after receiving a random access message from an UE on a physical random access channel an access point AP is configured to send a RACH Response. One problem here is that in current LTE the response (denoted typically as Msg2) is transmitted on physical downlink shared channel PDSCH with a downlink grant and resource scheduling in common search space scrambled with random access Radio Network Temporary Identitier RA-RNTI. Without any common information broadcasted from possible APs, the UE has no idea how downlink control channel is configured at each of the APs, and thus cannot find the downlink grant.

Figure 2 is a flowchart illustrating an embodiment of the invention. The embodiment starts at step 200. The flowchart illustrates the operation of user equipment or a part of the user equipment.

In step 202, the apparatus is configured to control the transmission of a random access message to an access point on a physical random access channel PRACH. In an embodiment, the UE transmits the message with no or very limited AP specific configuration.

A number of PRACH configurations can be specified beforehand and the UE may select one of them according given rules. The PRACH message may be received by multiple APs which are listening PRACH with UE-selected configuration

In step 204, the apparatus is configured to control the reception of a response on physical downlink shared channel PDSCH. The response does not comprise downlink control information on physical downlink control channels.

In step 206, the apparatus is configured to obtain one or more access point-specific configurations and determine resources for uplink transmission utilizing the response.

The process ends in step 208.

In prior art LTE the grant for Msg2 is with DCI (Downlink Control Information) Format 1A, and the key information includes modulation and coding scheme MCS index and resource allocation. In the present solution, proposed Msg2 comprises uplink grant for the UE but there is no downlink control information DCI on downlink control channels. Considering the importance of Msg2 and relative small Transport Block Size TBS, conservative MCS can be always used. For example, the UE may assume modulation and coding scheme index IMCS always as 0. The number of Physical resource Blocks PRBs allocated can also be fixed beforehand by considering the TBS.

The exact PRB allocation used by the access point in the transmission of Msg2 can be derived from RA-RNTI . The RA-RNTI is determined by the AP from the resources used by the UE when transmitting random access message on PRACH. Thus, the RA_RNTI depends on the time-frequency position of PRACH which is known by both UE and APs. If UE has some prior knowledge about the potential accessible APs, the AP-specific information (such as AP id) may also be one factor to determine the PRB allocation of response message. Alternatively UE may also try to blindly decode some possible positions.

The UE may be able to decode multiple response messages and thus could measure the signal strengths from multiple APs, and further determine a preferred AP. UE can transmit a message (Msg3 in LTE terminology) based on the AP response (Msg2).

Figure 3 is a flowchart illustrating an embodiment of the invention. The embodiment starts at step 300. The flowchart illustrates the operation of an access point or a part of the access point.

In step 302, the apparatus is configured to control the reception of a random access message from user equipment on a physical random access channel PRACH.

In step 304, the apparatus is configured to control the transmission of a response on physical downlink shared channel without downlink control information from physical downlink control channels.

The process ends in step 306.

The APs receiving the random access message from the UE and which want to accommodate the UE will transmit the response (Msg2 in LTE terminology), which is the first dedicated message from an AP to the UE. In an embodiment, important AP-specific configurations can be included in the message. For example, the configuration of control region and the reference signal for radio resource management (RRM) measurement may be included.

In an embodiment, the access point is configured to use predetermined resources when transmitting the response. The access point may be configured to apply predefined modulation and coding scheme MCS when transmitting the response.

In an embodiment, the access point is configured to determine resources used to transmit the response from resources used in the transmission of the random access message.

In an embodiment, the Transmission Block Size TBS of the response is fixed. As a predefined MCS may be used, the number of Physical resource Blocks PRB will also be pre-known to the UE. One example to determine the PRB position assuming 3 -PRB is as follows: first PRB index = RA-RNTI, second PRB index= RA-RNTI + roundup(BW/3), and last PRB index= RA-RNTI + 2 ^* roundup(BW/3), where BW denotes bandwidth. The three PRBs used to transmit the response are thus evenly distributed over system bandwidth.

Figure 4A illustrates a simplified example of a device in which some embodiments of the invention may be applied. In some embodiments, the device may be an access point, a base station or an eNodeB of a communication system or network. The device may be a part or a section of an access point, base station or eNodeB.

Figure 4B illustrates a simplified example of a device in which some embodiments of the invention may be applied. In some embodiments, the device may be user equipment UE or a respective device communicating with an access point, a base station or a NodeB of a communications system. The device may be a part or a section of user equipment.

It should be understood that the apparatuses are depicted herein as examples illustrating some embodiments. It is apparent to a person skilled in the art that the devices may also comprise other functions and/or structures and not all described functions and structures are required. Although the devices have been depicted as single entities, different modules and memory may be implemented in one or more physical or logical entities. In addition, each device may be a part of another device.

Referring to Figure 4A, the device of the example includes one or more control circuitries or processing circuits (CNTL) 400 configured to control at least part of the operation of the device.

The device may comprise one or more memories (MEM) 402 for storing data. Furthermore the memory may store software (PROG) 404 executable by the control circuitry 400. The memory may be integrated in the control circuitry.

The device may comprise a transceiver (TRX) 406. The transceiver is operationally connected to the control circuitry 400. It may be connected to an antenna arrangement (not shown). The device may also comprise a connection to a transceiver instead of a transceiver.

The device may comprise an interface (IF) 408. The interface is operationally connected to the control circuitry 400. The device may be connected to other network elements of the communication system or network via the interface. The software 404 may comprise a computer program comprising program code means adapted to cause the control circuitry 400 of the device to control a transceiver 406.

The software 404 may comprise a computer program comprising program code means adapted to cause the control circuitry 400 of the device to control the reception of a random access message from user equipment on a physical random access channel and control the transmission of a response on physical downlink shared channel without including information on resource allocation and uplink transmission grant in the response.

Figure 4B illustrates a simplified example of user equipment UE or a respective device. The device of the example includes one or more control circuitries or processing circuits (CNTL) 420 configured to control at least part of the operation of the device.

The device may comprise one or more memories (MEM) 422 for storing data. Furthermore the memory may store software (PROG) 424 executable by the control circuitry 420. The memory may be integrated in the control circuitry.

The device may comprise a transceiver (TRX) 426. The transceiver is operationally connected to the control circuitry 420. It may be connected to an antenna arrangement (not shown). The device may also comprise a connection to a transceiver instead of a transceiver.

The software 424 may comprise a computer program comprising program code means adapted to cause the control circuitry 420 of the device to control a transceiver 426.

The software 424 may comprise a computer program comprising program code means adapted to cause the control circuitry 400 of the device to control the transmission of a random access message to an access point on a physical random access channel; control the reception of a response on physical downlink shared channel; and determine resources for uplink transmission without utilizing the response.

The device may further comprise user interface (Ul) 428 operationally connected to the control circuitry 420. The user interface may comprise a display which may be touch sensitive, a keyboard or keypad, a microphone and a speaker, for example.

It should be understood that the devices are depicted herein as examples illustrating some embodiments. It is apparent to a person skilled in the art that the devices may also comprise other functions and/or structures and not all described functions and structures are required. Although both devices have been depicted as one entity, different modules and memory may be implemented in one or more physical or logical entities.

The steps and related functions described in the above and attached figures are in no absolute chronological order, and some of the steps may be performed simultaneously or in an order differing from the given one. Other functions can also be executed between the steps or within the steps. Some of the steps can also be left out or replaced with a corresponding step.

The apparatuses or controllers able to perform the above-described steps may be implemented as an electronic digital computer, or a circuitry which may comprise a working memory (RAM), a central processing unit (CPU), and a system clock. The CPU may comprise a set of registers, an arithmetic logic unit, and a controller. The controller or the circuitry is controlled by a sequence of program instructions transferred to the CPU from the RAM. The controller may contain a number of microinstructions for basic operations. The implementation of microinstructions may vary depending on the CPU design. The program instructions may be coded by a programming language, which may be a high-level programming language, such as C, Java, etc., or a low-level programming language, such as a machine language, or an assembler. The electronic digital computer may also have an operating system, which may provide system services to a computer program written with the program instructions.

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) combinations of circuits and software (and/or firmware), such as (as applicable): (i) a combination of processor(s) or (ii) portions of processor(s)/software including digital signal processor(s), software, and memory(ies) that work together to cause an apparatus to perform various functions, and (c) circuits, such as a microprocessor(s) or a portion of a microprocessor(s), that require software or firmware for operation, even if the software or firmware is not physically present.

This definition of 'circuitry' applies to all uses of this term in this application. 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 a 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 element, a baseband integrated circuit or applications processor integrated circuit for a mobile phone or a similar integrated circuit in a server, a cellular network device, or another network device.

An embodiment provides a computer program embodied on a distribution medium, comprising program instructions which, when loaded into an electronic apparatus, are configured to control the apparatus to execute the embodiments described above.

The computer program may be in source code form, object code form, or in some intermediate form, and it may be stored in some sort of carrier, which may be any entity or device capable of carrying the program. Such carriers include a record medium, computer memory, read-only memory, and a software distribution package, for example. Depending on the processing power needed, the computer program may be executed in a single electronic digital computer or it may be distributed amongst a number of computers.

The apparatus may also be implemented as one or more integrated circuits, such as application-specific integrated circuits ASIC. Other hardware embodiments are also feasible, such as a circuit built of separate logic components. A hybrid of these different implementations is also feasible. When selecting the method of implementation, a person skilled in the art will consider the requirements set for the size and power consumption of the apparatus, the necessary processing capacity, production costs, and production volumes, for example.

It will be obvious to a person skilled in the art that, as technology advances, the inventive concept can be implemented in various ways. The invention and its embodiments are not limited to the examples described above but may vary within the scope of the claim.

Claims

WHAT IS CLAIMED IS:

1 . An apparatus in a communication system, comprising: at least one processor; and

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

control the transmission of a random access message to an access point on a physical random access channel without access point-specific configuration;

control the reception of a response to the random access message on physical downlink shared channel without downlink control information from physical downlink control channels; and

obtain one or more access point-specific configurations and determine resources for uplink transmission utilizing the response.

2. The apparatus of claim 1 , the apparatus being configured to determine resources used to receive the response from resources used to transmit the random access message.

3. The apparatus of claim 1 , the apparatus being configured to select predetermined determine resources for response reception.

4. The apparatus of claim 1 or 2, the apparatus being configured to determine physical resource block allocation for response receptionfrom resources used to transmit the random access message.

5. The apparatus of any preceding claim, the apparatus being configured to apply predefined modulation and coding scheme in the response reception.

6. An apparatus in a communication system, comprising: at least one processor; and

at least one memory including computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to perform: control the reception of a random access message from user equipment on a physical random access channel;

control the transmission of a response on physical downlink shared channel without downlink control information from physical downlink control channels.

7. The apparatus of claim 6, the apparatus being configured to include in the response access point specific information.

8. The apparatus of claim 7, the apparatus being configured to include in the response a reference signal for radio resource management measurement.

9. The apparatus of any preceding claim 6 to 8, the apparatus being configured to use predetermined resources when transmitting the response.

10. The apparatus of any preceding claim 6 to 8, the apparatus being configured to apply predefined modulation and coding scheme when transmitting the response.

1 1 . The apparatus of any preceding claim 6 to 8, the apparatus being configured to determine resources used to transmit the response from resources used in the transmission of the random access message.

12. A method in a communication system, comprising:

controlling the transmission of a random access message to an access point on a physical random access channel without access point- specific configuration;

controlling the reception of a response to the random access message on physical downlink shared channel without downlink control information from physical downlink control channels; and

obtaining one or more access point-specific configurations and determining resources for uplink transmission utilizing the response.

13. The method of claim 12, further comprising: determining resources used in receiving the response from resources used to transmit the random access message.

14. The method of claim 12, further comprising: selecting predetermined determine resources for response reception.

15. The method of claim 12, 13 or 14, further comprising: determining physical resource block allocation response reception from resources used to transmit the random access message.

16. The method of any preceding claim 12 to 15, further comprising: applying predefined modulation and coding scheme in the response reception.

17. A method in a communication system, comprising:

controlling the reception of a random access message from user equipment on a physical random access channel; and

controlling the transmission of a response on physical downlink shared channel without downlink control information from physical downlink control channels.

18. The method of claim 17, further comprising: including in the response access point specific information.

19. The method of claim 17, further comprising: including in the response a reference signal for radio resource management measurement.

20. The method of any preceding claim 17 to 19, further comprising: using predetermined resources when transmitting the response.

21. The method of any preceding claim 17 to 20, further comprising: applying predefined modulation and coding scheme when transmitting the response.

22. The method of any preceding claim 17 to 19, further comprising: determining resources used to transmit the response from resources used in the transmission of the random access message.

23. A computer program product embodied on a distribution medium readable by a computer and comprising program instructions which, when loaded into an apparatus, execute the method according to any of claims 12 to 22.