WO2009004552A1

WO2009004552A1 - Improved relay node operation in a communication system

Info

Publication number: WO2009004552A1
Application number: PCT/IB2008/052598
Authority: WO
Inventors: Zhuyan Zhao; Xiao Yi Wang; Hao Guan; Xin Qi
Original assignee: Nokia Corporation; Nokia, Inc.
Priority date: 2007-06-29
Filing date: 2008-06-27
Publication date: 2009-01-08

Abstract

In one exemplary embodiment, a method includes: identifying, based on an allocation for a time division communication link between an access node (AN) and an end node (EN) via a relay node (RN), at least one relay switch point (RSP), the allocation including a plurality of time intervals, each interval corresponding to one of a first uplink (UL1) from the EN to the RN, a second uplink (UL2) from the RN to the AN, a first downlink (DL1) from the AN to the RN or a second downlink (DL2) from the RN to the EN, the at least one RSP corresponding to at least one of a transition between UL1 and UL2 or a transition between DL1 and DL2 (101); and signaling information indicative of the at least one RSP or indicative of a pattern including the at least one RSP from the AN towards the RN (102).

Description

IMPROVED RELAY NODE OPERATION IN A COMMUNICATION SYSTEM

TECHNICAL FIELD:

The exemplary and non-limiting embodiments of this invention relate generally to communication systems, apparatus, methods and computer program products and, more specifically, relate to communication systems utilizing at least one relay node.

BACKGROUND:

The following abbreviations are utilized herein:

3 G third generation of GSM-based mobile networks 3GPP third generation partnership project

AN access node

AOA angle of arrival

AP access point

BS base station CDMA code division multiple access

CWTS China wireless telecommunications standard

DL downlink (AN to EN)

EN end node

E-UTRAN evolved universal terrestrial radio access network FDMA frequency division multiple access

HSDPA high speed downlink packet access

ITU-R international telecommunications union - radio communications

LCR low chip rate

LTE long term evolution of UTRAN (E-UTRAN) MBSFN multicast broadcast single frequency network

Node B base station

OFDMA orthogonal frequency division multiple access

R4 release 4 R5 release 5

RN relay node

RS relay station

RSP relay switch point SP switch point

TDD time division duplex

TDMA time division multiple access

TD-SCDMA time division synchronous code division multiple access

UE user equipment, such as a mobile station, mobile terminal or mobile node UL uplink (EN to AN)

UTRAN universal terrestrial radio access network

ITU-R resolutions (RA-2000) approved the recommendations for 3 G mobile communication technology specifications, including those relating to TD-SCDMA, in May 2000. In March 2001, TD-SCDMA was accepted by 3GPP as a 3G Standard and was included in R4. The improved R4 and R5 specifications have newly added function points including HSDPA, air interface base station synchronization and terminal location (AOA-aided location).

TD-SCDMA is a 3 G wireless telecommunications standard developed by the CWTS group. TD-SCDMA is a flexible combination of three basic transmission modes: FDMA, TDMA and CDMA, featuring a large system capacity, a high use rate of spectrum and strong anti-interference capability. CMCC, an operator in China, has made the decision to deploy a TD-SCDMA system in China.

Reference in regard to TD-SCDMA systems may be made to 3GPP TS 25.221 V7.3.0, "3rd Generation Partnership Project; Technical Specification Group Radio Access Network; Physical channels and mapping of transport channels onto physical channels (TDD) (Release 7)," May 2007.

SUMMARY:

The below summary section is intended to be merely exemplary and non-limiting. In one non-limiting, exemplary embodiment of the invention, a method comprising: identifying, based on a resource allocation, at least one relay switch point (RSP), wherein the resource allocation is for a time division communication link between an access node (AN) and an end node (EN) via an intermediate relay node (RN) in a communication system, wherein the resource allocation comprises a plurality of time intervals, wherein each time interval corresponds to one of a first uplink portion (ULl) for communication from the EN to the RN, a second uplink portion (UL2) for communication from the RN to the AN, a first downlink portion (DLl) for communication from the AN to the RN or a second downlink portion (DL2) for communication from the RN to the EN, wherein the at least one RSP corresponds to at least one of a first transition between an ULl and an UL2 or a second transition between a DLl and a DL2; and signaling information indicative of the at least one RSP or indicative of a pattern comprising the at least one RSP from the AN towards the RN.

In another non-limiting, exemplary embodiment, an apparatus comprising: means for identifying, based on a resource allocation, at least one relay switch point (RSP), wherein the resource allocation is for a time division communication link between the apparatus and an end node (EN) via an intermediate relay node (RN) in a communication system, wherein the resource allocation comprises a plurality of time intervals, wherein each time interval corresponds to one of a first uplink portion (ULl) for communication from the EN to the RN, a second uplink portion (UL2) for communication from the RN to the apparatus, a first downlink portion (DLl) for communication from the apparatus to the RN or a second downlink portion (DL2) for communication from the RN to the EN, wherein the at least one RSP corresponds to at least one of a first transition between an ULl and an UL2 or a second transition between a DLl and a DL2; and means for signaling information indicative of the at least one RSP or indicative of a pattern comprising the at least one RSP from the apparatus towards the RN.

In another non-limiting, exemplary embodiment, a program storage device readable by a machine, tangibly embodying a program of instructions executable by the machine for performing operations, said operations comprising: identifying, based on a resource allocation, at least one relay switch point (RSP), wherein the resource allocation is for a time division communication link between an access node (AN) and an end node (EN) via an intermediate relay node (RN) in a communication system, wherein the resource allocation comprises a plurality of time intervals, wherein each time interval corresponds to one of a first uplink portion (ULl) for communication from the EN to the RN, a second uplink portion (UL2) for communication from the RN to the AN, a first downlink portion (DLl) for communication from the AN to the RN or a second downlink portion (DL2) for communication from the RN to the EN, wherein the at least one RSP corresponds to at least one of a first transition between an ULl and an UL2 or a second transition between a DLl and a DL2; and signaling information indicative of the at least one RSP or indicative of a pattern comprising the at least one RSP from the AN towards the RN.

In another non-limiting, exemplary embodiment, an apparatus comprising: a data processor configured to identify, based on a resource allocation, at least one relay switch point (RSP), wherein the resource allocation is for a time division communication link between the apparatus and an end node (EN) via an intermediate relay node (RN) in a communication system, wherein the resource allocation comprises a plurality of time intervals, wherein each time interval corresponds to one of a first uplink portion (ULl) for communication from the EN to the RN, a second uplink portion (UL2) for communication from the RN to the apparatus, a first downlink portion (DLl) for communication from the apparatus to the RN or a second downlink portion (DL2) for communication from the RN to the EN, wherein the at least one RSP corresponds to at least one of a first transition between an ULl and an UL2 or a second transition between a DLl and a DL2; and a transmitter configured to signal information indicative of the at least one RSP or indicative of a pattern comprising the at least one RSP from the apparatus towards the RN.

In another non-limiting, exemplary embodiment, a method comprising: receiving information indicative of at least one relay switch point (RSP) or indicative of a pattern comprising the at least one RSP, wherein the information is received within a communication system that at least partially utilizes a time division communication link between an access node (AN) and an end node (EN) via an intermediate relay node (RN), wherein resources for the time division communication link are allocated according to a resource allocation comprising a plurality of time intervals, wherein each time interval corresponds to one of a first uplink portion (ULl) for communication from the EN to the RN, a second uplink portion (UL2) for communication from the RN to the AN, a first downlink portion (DL 1 ) for communication from the AN to the RN or a second downlink portion (DL2) for communication from the RN to the EN, wherein the at least one RSP corresponds to at least one of a first transition between an ULl and an UL2 or a second transition between a DLl and a DL2; and using the received information to schedule at least one transmission or at least one reception in accordance with the at least one RSP.

In another non-limiting, exemplary embodiment, an apparatus comprising: means for receiving information indicative of at least one relay switch point (RSP) or indicative of a pattern comprising the at least one RSP, wherein the information is received within a communication system that at least partially utilizes a time division communication link between a source node (SN) and an end node (EN) via an intermediate relay node (RN), wherein resources for the time division communication link are allocated according to a resource allocation comprising a plurality of time intervals, wherein each time interval corresponds to one of a first uplink portion (ULl) for communication from the EN to the RN, a second uplink portion (UL2) for communication from the RN to the SN, a first downlink portion (DL 1 ) for communication from the SN to the RN or a second downlink portion (DL2) for communication from the RN to the EN, wherein the at least one RSP corresponds to at least one of a first transition between an ULl and an UL2 or a second transition between a DLl and a DL2; and means for using the received information to schedule at least one transmission or at least one reception in accordance with the at least one RSP.

In another non- limiting, exemplary embodiment, a program storage device readable by a machine, tangibly embodying a program of instructions executable by the machine for performing operations, said operations comprising: receiving information indicative of at least one relay switch point (RSP) or indicative of a pattern comprising the at least one RSP, wherein the information is received within a communication system that at least partially utilizes a time division communication link between a source node (SN) and an end node (EN) via an intermediate relay node (RN), wherein resources for the time division communication link are allocated according to a resource allocation comprising a plurality of time intervals, wherein each time interval corresponds to one of a first uplink portion (ULl) for communication from the EN to the RN, a second uplink portion (UL2) for communication from the RN to the SN, a first downlink portion (DLl) for communication from the SN to the RN or a second downlink portion (DL2) for communication from the RN to the EN, wherein the at least one RSP corresponds to at least one of a first transition between an ULl and an UL2 or a second transition between a DLl and a DL2; and using the received information to schedule at least one transmission or at least one reception in accordance with the at least one RSP.

In another non-limiting, exemplary embodiment, an apparatus comprising: a receiver configured to receive information indicative of at least one relay switch point (RSP) or indicative of a pattern comprising the at least one RSP, wherein the information is received within a communication system that at least partially utilizes a time division communication link between a source node (SN) and an end node (EN) via an intermediate relay node (RN), wherein resources for the time division communication link are allocated according to a resource allocation comprising a plurality of time intervals, wherein each time interval corresponds to one of a first uplink portion (ULl) for communication from the EN to the RN, a second uplink portion (UL2) for communication from the RN to the SN, a first downlink portion (DLl) for communication from the SN to the RN or a second downlink portion (DL2) for communication from the RN to the EN, wherein the at least one RSP corresponds to at least one of a first transition between an ULl and an UL2 or a second transition between a DL 1 and a DL2; and a processor configured to use the received information to schedule at least one transmission or at least one reception in accordance with the at least one RSP.

BRIEF DESCRIPTION OF THE DRAWINGS:

The foregoing and other aspects of exemplary embodiments of this invention are made more evident in the following Detailed Description, when read in conjunction with the attached Drawing Figures, wherein:

FIG. 1 shows the physical channel signal format for 1.28 Mcps TDD, as depicted in FIG. 18A of TS 25.221 V7.3.0; FIG. 2 shows the structure of a sub-frame for the 1.28 Mcps TDD option, as depicted in FIG. 18B of TS 25.221 V7.3.0;

FIG. 3 depicts an exemplary relay system within which the exemplary embodiments of the invention may be practiced;

FIG. 4 illustrates another exemplary communication system within which the exemplary embodiments of the invention may be practiced;

FIG. 5 depicts an exemplary TD-SCDMA sub-frame incorporating aspects of the exemplary embodiments of the invention;

FIG. 6 illustrates one exemplary relay switch point (RSP) pattern for four sub-carriers;

FIG. 7 illustrates another exemplary RSP pattern for four sub-carriers;

FIG. 8 shows a simplified block diagram of various electronic devices that are suitable for use in practicing the exemplary embodiments of this invention;

FIG. 9 depicts a flowchart illustrating one non-limiting example of a method for practicing the exemplary embodiments of this invention; and

FIG. 10 depicts a flowchart illustrating another non-limiting example of a method for practicing the exemplary embodiments of this invention.

DETAILED DESCRIPTION:

In communication systems (e.g., mobile communication systems such as cellular networks, for example), one challenge is to have high data rate coverage. Usually only terminals close to the AP (e.g., a BS) have a high data rate. A large number of APs may be used to attain continuous high data rate coverage. One promising alternative technique is to use relay stations to distribute the data rate more evenly in the coverage area.

Relaying allows for the forwarding of data, for example, using intelligently located fixed relay nodes (e.g., wireless routers). This can potentially improve network coverage by providing connections for users in shadowed locations as well as extending the BS coverage beyond the regular boundaries. Particularly in CDMA systems (where capacity may be interference limited), the corresponding reduction in terminal transmit power may lead to a reduction in interference and, hence, an improvement in capacity and spectrum efficiency. Additional benefits in terms of battery saving can also be realized.

TD-SCDMA is one exemplary system within which the exemplary embodiments of the invention, as further described below, can be practiced. For example, section 5 A of TS 25.221 V7.3.0 describes the physical channels for the 1.28 Mcps option of a TD-SCDMA system. FIG. 1 shows the physical channel signal format for 1.28 Mcps TDD, as depicted in FIG. 18A of TS 25.221 V7.3.0. As specified, a TDMA frame has a duration of 10 ms and is divided into two sub-frames of 5 ms each. As shown in FIG. 1 , and as further described in the specifications (e.g., TS 25.221 V7.3.0), the frame structure for each sub- frame is the same.

FIG. 2 shows the structure of a sub-frame for the 1.28 Mcps TDD option, as depicted in FIG. 18B ofTS 25.221 V7.3.0. The sub-frame has seven time slots, numbered from 0 to 6, with each time slot having a duration of 864 chips. The sub-frame also includes a downlink pilot time slot (DwPTS) having a duration of 96 chips, an uplink pilot time slot (UpPTS) having a duration of 160 chips and a main guard period (GP) having a duration of 96 chips. In some exemplary embodiments, time slot#0 is always allocated as DL while time slot#l is always allocated as UL. In FIG. 2, note that time slots with an upward-pointing arrow indicate UL slots while those with a downward-pointing arrow indicate DL slots.

The time slots for the UL and the DL are separated by switching points. That is, between the DL time slots and the UL time slots is a switching point to separate the UL and DL. In some exemplary embodiments, each sub-frame has two switching points (UL to DL and vice versa). The 1.28 Mcps TDD option can operate in symmetric (a same number of DL slots and UL slots) or asymmetric (different numbers of DL slots and UL slots) modes by properly configuring the number of DL and UL time slots. Generally, at least one time slot (time slot #0, for example) is allocated for the DL and at least one time slot (time slot #1, for example) is allocated for the UL. However, in the case where the entire carrier is dedicated to MBSFN, no UL timeslot is used and DwPTS and UpPTS are not transmitted.

FIG. 3 depicts an exemplary communication system 10 within which the exemplary embodiments of the invention may be practiced, as described in greater detail below. The system 10 includes a UE 12, a RS (relay) 14 and a BS 16. The relay 14 is disposed between the UE 12 and the BS 16. The relay 14 may comprise a simple repeater-type structure which facilitates communication between the UE 12 and the BS 16. There is a first bidirectional wireless communication link 18 between the relay 14 and the BS 16. There is a second bidirectional wireless communication link 20 between the relay 14 and the UE 12. Although shown in FIG. 3 with only one UE 12, the relay 14 may communicate with a plurality of UEs. Generally, the relay 14 is dedicated to a single BS 16. In some exemplary embodiments, the relay 14 communicates with the BS 16 via a high gain directional antenna in order to reduce interference. In further exemplary embodiments, the relay 14 communicates with the UE 12 via a conventional omnidirectional antenna. Generally, the complexity and cost of the relay 14 is intended to be small relative to that of the BS 16. As shown in FIG. 3, the relay 14 may communicate with the UE 12 and the BS 16 at substantially the same time.

FIG. 4 illustrates another exemplary communication system 22 within which the exemplary embodiments of the invention may be practiced. The system 22 includes a RN 26 disposed between an EN 24 and an AN 28. The RN 26 facilitates communication between the EN 24 and the AN 28 via UL (EN 24 to AN 28) and DL (AN 28 to EN 24) communication links. For convenience, in FIG. 4, the UL and DL communication links have been broken into two sections. That is, the UL is comprised of an ULl (EN 24 to RN 26) and an UL2 (RN 26 to AN 28). The DL is comprised of a DLl (AN 28 to RN 26) and a DL2 (RN 26 to EN 24). One or more of the EN 24, the RN 26 and the AN 28 may comprise a mobile node (e.g., a mobile phone, a mobile relay). One or more of the EN 24, the RN 26 and the AN 28 may comprise a fixed node. The AN 28 may comprise a base station or an access point, as non-limiting examples. As a non-limiting example, the system 22 may comprise a wireless communication system. As a further non-limiting example, the system 22 may comprise a TD-SCDMA system. As a non-limiting example, the EN 24 may comprise a UE.

In the DL, to relay a data packet from the AN 28 to the EN 24, the RN 26 should generally first receive the data packet in the DLL If the data packet is decoded successfully, the RN 26 can re-encode the information to form a new relay data packet and send the new packet towards the EN 24 via DL2. In the UL, similar operations take place. In other exemplary embodiments, the RN 26 does not decode and re-encode the data packet. For example, the RN 26 may simply amplify the signal received via DLl and retransmit the data packet towards the EN 24 via DL2.

Due to the dual transmission in one direction (e.g., DLl and DL2), if the RN 26 is utilized, the relayed users (EN 24) generally consume twice as many resources (e.g., spreading codes, slots) as compared to non-relayed users. Various solutions have been presented to improve the efficiency of such a system, including code sharing (the relay uses spreading codes belonging to the associated BS) and code reuse (the relay reuses the BS code using different scrambling codes). Reference in regard to such proposals may be made to Tameh et al., "The Use of Intelligently Deployed Fixed Relays to Improve the Performance of a UTRA-TDD System," IEEE 58th Vehicular Technology Conference, 2003 (VTC 2003 -Fall). In another conventional wireless system, a relay zone (Relay_Zone) may be used for data communication between a BS and a RS. Reference in this regard may be made to 802.16j-06/026r4, "Baselines Document for Draft Standard for Local and Metropolitan Area Networks; Part 16: Air Interface for Fixed and Mobile Broadband Wireless Access Systems; Multihop Relay Specification," June 6, 2007.

In a TD-SCDMA system, the relay cannot transmit and receive data at the same time (i.e., in a single time slot) since the UL and DL are time-multiplexed. However, to relay data between the UE and BS, it is generally preferable that the relay both transmit to the BS (UL) and receive from the BS (DL) within a single frame or sub-frame (e.g., in a single UL slot or a single DL slot).

Exemplary embodiments of the invention provide for improved operation of a relay node within a communication system (e.g., for time division communication). At least one relay switch point is identified. A relay switch point occurs when consecutive time intervals (e.g., time slots) are for DLl and DL2 or for ULl and UL2. In some exemplary embodiments, a special slot is allocated for each relay switch point. The relay switch point(s), once identified, are signaled to at least the RN 26. In further exemplary embodiments, the relay switch point(s) are also signaled to the EN 24.

FIG. 5 depicts an exemplary TD-SCDMA sub-frame 38 incorporating aspects of the exemplary embodiments of the invention. The sub-frame 38 includes two switching points (SPs), one for a transition from DL to UL (SPl) and one for a transition from UL to DL (SP2). The sub-frame also includes two relay switching points (RSPs), one for a transition from ULl to UL2 (RSPl) and one for a transition from DL2 to DLl (RSP2), in accordance with the exemplary embodiments of the invention.

In some exemplary embodiments, the relay switch point(s) (e.g., location, number, usage of) are decided by the radio access network. In further exemplary embodiments, the relay switching point(s) are determined by the radio access network according to application requirements. In further exemplary embodiments, information comprising or corresponding to the relay switching point(s) is sent through broadcasting signaling (e.g., from the AN 28 to the RN 26 or from the AN 28 to the EN 24 and the RN 26). In further exemplary embodiments, in response to receiving the information comprising or corresponding to the RSP(s), the RN forwards the information to the EN.

In one exemplary multicarrier system, the relay switch point(s) are signaled (e.g., broadcast) for each (every) carrier.

In another exemplary multicarrier system, a relay switch point (RSP) pattern is utilized and there is no need to signal (e.g., broadcast) the relay switch point(s) for every carrier. The RSP pattern describes a pattern of the relay switch points for all of the carriers. As a non-limiting example, the RSP pattern may be identified by n bits of information. For example, 4 bits of information may be used, thus allowing for up to 16 different patterns.

In such a manner, instead of signaling the relay switch points for all of the carriers, only the 4-bit representation of a selected RSP pattern is signaled. In some exemplary embodiments, the possible RSP patterns are predefined. In further exemplary embodiments, the possible RSP patterns are known in advance at least by the RN 26 or at least by the RN 26 and the EN 24.

FIG. 6 illustrates one exemplary RSP pattern 40 for four sub-carriers (Cl, C2, C3, C4). FIG. 7 illustrates another exemplary RSP pattern 42 for four sub-carriers (C5, C6, C7, C8). It is noted that the RSP patterns shown in FIGS. 6 and 7 are intended as non- limiting examples for various implementations of exemplary embodiments of the invention. In practice, any suitable RSP pattern may be utilized. Furthermore, the RSP pattern may utilize a different number of sub-carriers and/or resources.

Reference is made to FIG. 8 for illustrating a simplified block diagram of various electronic devices that are suitable for use in practicing the exemplary embodiments of this invention. In FIG. 8, a communication system 48 includes aNodeO (NO) 50, aNodel (Nl) 60 and aNode2 (N2) 70. As non-limiting examples, the communication system 48 may comprise a network, a wireless network, a cellular network (e.g., a TDMA system, a FDMA system, a CDMA system, an OFDMA system, a 3G system, a TD-SCDMA system), a WAN, a WLAN, a short-range wireless network, a Bluetooth® system or a WiMAX system.

The NO 50 includes: a data processor (DPO) 52; a memory (MEMO) 54 coupled to the DPO 52; a suitable RF transceiver (TRANSO) 56 (having a transmitter (TX) and a receiver (RX)) coupled to the DPO 52; and a suitable antenna (ANTO) 57 coupled to the

TRANSO 56. The MEMO 54 stores aprogram (PROGO) 58. The TRANSO 56 is capable of wireless communication with the Nl 60 (via a first communication link 82). The NO

50 may comprise a BS, a Node B, an AN, an access gateway, a mobile node or a UE, as non-limiting examples. As a non-limiting example, the NO 50 may generally be seen to correspond to the AN, as discussed elsewhere herein (e.g., the AN 28).

In some exemplary embodiments, the NO 50 may be coupled to other electronic devices, such as one or more BSs, access gateways, access nodes, network elements or networks. As a non-limiting example, the NO 50 may be coupled to the internet 86 via a communication link 88. In other exemplary embodiments, one or both of the Nl 60 and the N2 70 can access the internet 86 by communicating with the NO 50.

The Nl 60 includes: a data processor (DPI) 62; a memory (MEMl) 64 coupled to the DPI 62; a suitable RF transceiver (TRANSl) 66 (having a transmitter (TX) and a receiver (RX)) coupled to the DPI 62; and a suitable antenna (ANTl) 67 coupled to the TRANSl 66. The MEMl 64 stores aprogram (PROGl) 68. The TRANSl 66 is capable of wireless communication with both the NO 50 (via the first communication link 82) and the N2 70 (via a second communication link 84). The Nl 60 may comprise a relay, a RN, a mobile RN, a fixed RN, a RS, a BS, an access node, an access gateway, a mobile node or a UE, as non-limiting examples. As a non-limiting example, the Nl 60 may generally be seen to correspond to the RN, as discussed elsewhere herein (e.g., the RN 26).

The N2 70 includes: a data processor (DP2) 72; a memory (MEM2) 74 coupled to the DP2 72; a suitable RF transceiver (TRANS2) 76 (having a transmitter (TX) and a receiver (RX)) coupled to the DP2 72; and a suitable antenna (ANT2) 77 coupled to the TRANS276. The MEM274 stores a program (PROG2) 78. The TRANS276 is capable of wireless communication with the Nl 60 (via the second communication link 84). The N2 70 may comprise a Node B, a BS, an access node, an access gateway, a mobile node, a fixed node or a UE, as non-limiting examples. As a non-limiting example, the N2 70 may generally be seen to correspond to the EN, as discussed elsewhere herein (e.g., the EN 24).

At least one of the PROGs 58, 68, 78 is assumed to include program instructions that, when executed by the associated DP, enable the respective electronic device(s) to operate in accordance with the exemplary embodiments of this invention, as discussed herein.

In general, the various exemplary embodiments of the nodes 50, 60, 70 can include, but are not limited to, cellular telephones, personal digital assistants (PDAs) having wired or wireless communication capabilities, portable computers having wired or wireless communication capabilities, desktop computers having wired or wireless communication capabilities, image capture devices such as digital cameras having wired or wireless communication capabilities, gaming devices having wired or wireless communication capabilities, music storage and playback appliances having wired or wireless communication capabilities, Internet appliances permitting wired or wireless Internet access and browsing, as well as units or terminals (fixed or portable) that incorporate combinations of such functions.

The exemplary embodiments of this invention may be implemented by computer software executable by one or more of the DPs 52, 62, 72 of the nodes 50, 60, 70, or by hardware, or by a combination of software and hardware. As a non-limiting example, the exemplary embodiments of the invention may be implemented by circuitry and/or one or more integrated circuits or processors.

The MEMs 54, 64, 74 may be of any type suitable to the local technical environment and may be implemented using any suitable data storage technology, such as semiconductor-based memory devices, magnetic memory devices and systems, optical memory devices and systems, fixed memory and removable memory, as non-limiting examples. The DPs 52, 62, 72 may be of any type suitable to the local technical environment, and may include one or more of general purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs) and processors based on a multi-core processor architecture, as non-limiting examples.

The configuration of the system and devices shown in FIG. 8 is provided only as one non- limiting example. One of ordinary skill in the art will appreciate other configurations that may be utilized in conjunction with aspects of the exemplary embodiments of the invention. As non-limiting examples of such other configurations, one or more of the nodes 50, 60, 70 may comprise any suitable number of data processors, memories, transceivers and/or antennas. For example, one or more of the nodes 50, 60, 70 may have a plurality of antennas and support multiple input/multiple output (MIMO) communication. Furthermore, the wireless communication system 48 may comprise additional nodes, such as additional UEs, BSs, ANs or RNs, as non-limiting examples. As a non-limiting example, multiple RNs or RSs may use any suitable method of cooperative diversity transmission. Below are provided further descriptions of non-limiting, exemplary embodiments. The below-described exemplary embodiments are separately numbered for clarity and identification. This numbering should not be construed as wholly separating the below descriptions since various aspects of one or more exemplary embodiments may be practiced in conjunction with one or more other aspects or exemplary embodiments as described herein.

(1) In one non-limiting, exemplary embodiment, and as illustrated in FIG. 9, a method comprising: identifying, based on a resource allocation, at least one relay switch point (RSP), wherein the resource allocation is for a time division communication link between an access node (AN) and an end node (EN) via an intermediate relay node (RN) in a communication system, wherein the resource allocation comprises a plurality of time intervals, wherein each time interval corresponds to one of a first uplink portion (ULl) for communication from the EN to the RN, a second uplink portion (UL2) for communication from the RN to the AN, a first downlink portion (DLl) for communication from the AN to the RN or a second downlink portion (DL2) for communication from the RN to the EN, wherein the at least one RSP corresponds to at least one of a first transition between an ULl and an UL2 or a second transition between a DLl and a DL2 (101); and signaling information indicative of the at least one RSP or indicative of a pattern comprising the at least one RSP from the AN towards the RN

(102).

In further exemplary embodiments: A method as described above, wherein signaling comprises transmitting at least one message. A method as in any previous method, wherein signaling comprises transmitting at least one broadcast message. A method as in any previous method, wherein signaling comprises broadcasting at least one message. A method as in any previous method, further comprising determining the resource allocation. A method as in any previous method, wherein the resource allocation is determined by a radio access network. A method as in any previous method, wherein the resource allocation is determined according to at least one application requirement. A method as in any previous method, wherein the time division communication link comprises a multi-carrier link. A method as in any previous method, wherein the time division communication link comprises a multi-carrier link and wherein at least two RSPs are signaled for at least two sub-carriers. A method as in any previous method, wherein the time division communication link comprises a multi-carrier link and further comprising signaling the pattern from the AN towards the RN or towards the RN and the EN.

A method as in the previous method, wherein the pattern is predefined. A method as in any previous method, wherein the pattern is known in advance by the RN or the RN and the EN. A method as in any previous method, wherein the pattern comprises an /7-bit representation. A method as in the previous one, wherein n = 4. A method as in any previous method, wherein the communication system comprises a wireless communication system. A method as in any previous method, wherein the communication system comprises a TD-SCDMA system. A method as in any previous method, wherein the EN comprises one of a mobile node, a UE, a portable computer, a desktop computer or a mobile phone. A method as in any previous method, wherein the AN comprises one of a BS, an AN, an access gateway, a mobile node or a UE. A method as in any previous method, wherein the RN comprises one of a mobile RN, a fixed RN, an AN, a mobile node or a UE.

A method as in any previous method, wherein the method is implemented by a computer program or a computer program product. A method as in any previous method, wherein the method is implemented by a program storage device readable by a machine, tangibly embodying a program of instructions executable by the machine for performing operations, said operations comprising the steps of performing the method. A method as in the previous, wherein the machine comprises the AN.

(2) In another non-limiting, exemplary embodiment, a program storage device readable by a machine, tangibly embodying a program of instructions executable by the machine for performing operations, said operations comprising: identifying, based on a resource allocation, at least one relay switch point (RSP), wherein the resource allocation is for a time division communication link between an access node (AN) and an end node (EN) via an intermediate relay node (RN) in a communication system, wherein the resource allocation comprises a plurality of time intervals, wherein each time interval corresponds to one of a first uplink portion (ULl) for communication from the EN to the RN, a second uplink portion (UL2) for communication from the RN to the AN, a first downlink portion (DLl) for communication from the AN to the RN or a second downlink portion (DL2) for communication from the RN to the EN, wherein the at least one RSP corresponds to at least one of a first transition between an ULl and an UL2 or a second transition between a DLl and a DL2 (101); and signaling information indicative of the at least one RSP or indicative of a pattern comprising the at least one RSP from the AN towards the RN (102).

In further exemplary embodiments: A program storage device as described above, wherein signaling comprises transmitting at least one broadcast message. A program storage device as in any previous, the operations further comprising determining the resource allocation. A program storage device as in any previous, wherein the resource allocation is determined by a radio access network. A program storage device as in any previous, wherein the resource allocation is determined according to at least one application requirement. A program storage device as in any previous, wherein the time division communication link comprises a multi-carrier link. A program storage device as in any previous, wherein the time division communication link comprises a multi-carrier link and wherein at least two RSPs are signaled for at least two sub-carriers. A program storage device as in any previous, wherein the time division communication link comprises a multi-carrier link, the operations further comprising signaling the pattern from the AN towards the RN or towards the RN and the EN.

A program storage device as in the previous, wherein the pattern is predefined. A program storage device as in any previous, wherein the pattern is known in advance by the RN or the RN and the EN. A program storage device as in any previous, wherein the pattern comprises an «-bit representation. A program storage device as in the previous one, where n = 4. A program storage device as in any previous, wherein the communication system comprises a wireless communication system. A program storage device as in any previous, wherein the communication system comprises a TD-SCDMA system. A program storage device as in any previous, wherein the EN comprises one of a mobile node, a UE, a portable computer, a desktop computer or a mobile phone. A program storage device as in any previous, wherein the AN comprises one of a BS, a mobile node or a UE. A program storage device as in any previous, wherein the RN comprises one of a mobile RN, a fixed RN, an AN, a mobile node or a UE.

(3) In another non-limiting, exemplary embodiment, an apparatus comprising: a data processor configured to identify, based on a resource allocation, at least one relay switch point (RSP), wherein the resource allocation is for a time division communication link between the apparatus and an end node (EN) via an intermediate relay node (RN) in a communication system, wherein the resource allocation comprises a plurality of time intervals, wherein each time interval corresponds to one of a first uplink portion (ULl) for communication from the EN to the RN, a second uplink portion (UL2) for communication from the RN to the apparatus, a first downlink portion (DLl) for communication from the apparatus to the RN or a second downlink portion (DL2) for communication from the RN to the EN, wherein the at least one RSP corresponds to at least one of a first transition between an ULl and an UL2 or a second transition between a DLl and a DL2; and a transmitter configured to signal information indicative of the at least one RSP or indicative of a pattern comprising the at least one RSP from the apparatus towards the RN.

In further exemplary embodiments: An apparatus as described above, wherein the transmitted signal comprises a broadcast message. An apparatus as in any previous apparatus, wherein the data processor is further configured to determine the resource allocation. An apparatus as in any previous apparatus, wherein the resource allocation is determined by a radio access network. An apparatus as in any previous apparatus, wherein the resource allocation is determined according to at least one application requirement. An apparatus as in any previous apparatus, wherein the time division communication link comprises a multi-carrier link. An apparatus as in any previous apparatus, wherein the time division communication link comprises a multi-carrier link and wherein at least two RSPs are signaled for at least two sub-carriers. An apparatus as in any previous apparatus, wherein the time division communication link comprises a multi-carrier link and wherein the transmitter is further configured to signal the pattern from the apparatus towards the RN or towards the RN and the EN.

An apparatus as in any previous apparatus, wherein the pattern is predefined. An apparatus as in any previous apparatus, wherein the pattern is known in advance by the RN or the RN and the EN. An apparatus as in any previous apparatus, wherein the pattern comprises an 77-bit representation. An apparatus as in the previous one, wherein n = 4. An apparatus as in any previous apparatus, wherein the communication system comprises a wireless communication system. An apparatus as in any previous apparatus, wherein the communication system comprises a TD-SCDMA system. An apparatus as in any previous apparatus, wherein the EN comprises one of a mobile node, a UE, a portable computer, a desktop computer or a mobile phone. An apparatus as in any previous apparatus, wherein the apparatus comprises one of a BS, an AN, an access gateway, a mobile node, a mobile phone or a UE. An apparatus as in any previous apparatus, wherein the RN comprises one of a mobile RN, a fixed RN, an AN, a mobile node or a UE. An apparatus as in any previous apparatus, further comprising a receiver. An apparatus as in any previous apparatus, further comprising a memory configured to store information. An apparatus as in any previous apparatus, wherein the apparatus is configured to transmit messages to the RN via the transmitter and to receive messages from the RN via a receiver.

(4) In another non-lirniting, exemplary embodiment, an apparatus comprising : for identifying, based on a resource allocation, at least one relay switch point (RSP), wherein the resource allocation is for a time division communication link between the apparatus and an end node (EN) via an intermediate relay node (RN) in a communication system, wherein the resource allocation comprises a plurality of time intervals, wherein each time interval corresponds to one of a first uplink portion (ULl) for communication from the EN to the RN, a second uplink portion (UL2) for communication from the RN to the apparatus, a first downlink portion (DLl) for communication from the apparatus to the RN or a second downlink portion (DL2) for communication from the RN to the EN, wherein the at least one RSP corresponds to at least one of a first transition between an ULl and an UL2 or a second transition between a DLl and a DL2; and means for signaling information indicative of the at least one RSP or indicative of a pattern comprising the at least one RSP from the apparatus towards the RN.

In further exemplary embodiments: An apparatus as described above, wherein the means for identifying comprises at least one data processor and wherein the means for signaling comprises at least one transmitter.

An apparatus as in any previous apparatus, wherein the transmitted signal comprises a broadcast message. An apparatus as in any previous apparatus, further comprising means for determining the resource allocation. An apparatus as in the previous apparatus, wherein the means for determining comprises the means for identifying and/or a data processor. An apparatus as in any previous apparatus, wherein the resource allocation is determined by a radio access network. An apparatus as in any previous apparatus, wherein the resource allocation is determined according to at least one application requirement. An apparatus as in any previous apparatus, wherein the time division communication link comprises a multi-carrier link. An apparatus as in any previous apparatus, wherein the time division communication link comprises a multi-carrier link and wherein at least two RSPs are signaled for at least two sub-carriers. An apparatus as in any previous apparatus, wherein the time division communication link comprises a multi-carrier link and wherein the means for signaling is further for signaling the pattern from the apparatus towards the RN or towards the RN and the EN.

An appaiatus as in any previous apparatus, wherein the pattern is predefined. An apparatus as in any previous apparatus, wherein the pattern is known in advance by at least one of the RN or the EN. An apparatus as in any previous apparatus, wherein the pattern comprises an n-bit representation. An apparatus as in the previous one, wherein n = 4. An apparatus as in any previous apparatus, wherein the communication system comprises a wireless communication system. An apparatus as in any previous apparatus, wherein the communication system comprises a TD-SCDMA system. An apparatus as in any previous apparatus, wherein the EN comprises one of a mobile node, a UE, a portable computer, a desktop computer or a mobile phone. An apparatus as in any previous apparatus, wherein the apparatus comprises one of a BS, an AN, an access gateway, a mobile node, a mobile phone or a UE. An apparatus as in any previous apparatus, wherein the RN comprises one of a mobile RN, a fixed RN, an AN, a mobile node or a UE. An apparatus as in any previous apparatus, further comprising means for receiving. An apparatus as in any previous apparatus, wherein the means for receiving comprises a receiver. An apparatus as in any previous apparatus, further comprising means for storing information. An apparatus as in any previous apparatus, wherein the means for storing comprises a memory. An apparatus as in any previous apparatus, wherein the apparatus is configured to transmit messages to the RN and to receive messages from the RN.

(5) In another non-limiting, exemplary embodiment, an apparatus comprising: identification circuitry configured to identify, based on a resource allocation, at least one relay switch point (RSP), wherein the resource allocation is for a time division communication link between the apparatus and an end node (EN) via an intermediate relay node (RN) in a communication system, wherein the resource allocation comprises a plurality of time intervals, wherein each time interval corresponds to one of a first uplink portion (UL 1 ) for communication from the EN to the RN, a second uplink portion (UL2) for communication from the RN to the apparatus, a first downlink portion (DLl) for communication from the apparatus to the RN or a second downlink portion (DL2) for communication from the RN to the EN, wherein the at least one RSP corresponds to at least one of a first transition between an ULl and an UL2 or a second transition between a DLl and a DL2; and signaling circuitry configured to signal information indicative of the at least one RSP or indicative of a pattern comprising the at least one RSP from the apparatus towards the RN.

An apparatus as in the previous, further comprising one or more additional aspects of the exemplary embodiments of the invention as described elsewhere herein.

(6) In another non-limiting, exemplary embodiment, and as illustrated in FIG. 10, a method comprising: receiving information indicative of at least one relay switch point (RSP) or indicative of a pattern comprising the at least one RSP, wherein the information is received within a communication system that at least partially utilizes a time division communication link between an access node (AN) and an end node (EN) via an intermediate relay node (RN), wherein resources for the time division communication link are allocated according to a resource allocation comprising a plurality of time intervals, wherein each time interval corresponds to one of a first uplink portion (ULl) for communication from the EN to the RN, a second uplink portion (UL2) for communication from the RN to the AN, a first downlink portion (DLl) for communication from the AN to the RN or a second downlink portion (DL2) for communication from the RN to the EN, wherein the at least one RSP corresponds to at least one of a first transition between an ULl and an UL2 or a second transition between a DLl and a DL2 (201); and using the received information to schedule at least one transmission or at least one reception in accordance with the at least one RSP (202).

A method as in the previous, wherein the method is implemented by the RN, the method further comprising: transmitting the information to the EN. A method as in any previous, wherein the method is implemented by the RN and/or the EN. A method as in any previous method, wherein the method is implemented by a computer program or a computer program product. A method as in any previous method, wherein the method is implemented by a program storage device readable by a machine, tangibly embodying a program of instructions executable by the machine for performing operations, said operations comprising the steps of performing the method. A method as in the previous, wherein the machine comprises the EN or the RN.

A method as in the previous, further comprising one or more additional aspects of the exemplary embodiments of the invention as described elsewhere herein.

(7) In another non-limiting, exemplary embodiment, a program storage device readable by a machine, tangibly embodying a program of instructions executable by the machine for performing operations, said operations comprising: receiving information indicative of at least one relay switch point (RSP) or indicative of a pattern comprising the at least one RSP, wherein the information is received within a communication system that at least partially utilizes a time division communication link between a source node (SN) and an end node (EN) via an intermediate relay node (RN), wherein resources for the time division communication link are allocated according to a resource allocation comprising a plurality of time intervals, wherein each time interval corresponds to one of a first uplink portion (ULl) for communication from the EN to the RN, a second uplink portion (UL2) for communication from the RN to the SN, a first downlink portion (DLl) for communication from the SN to the RN or a second downlink portion (DL2) for communication from the RN to the EN, wherein the at least one RSP corresponds to at least one of a first transition between an ULl and an UL2 or a second transition between a DLl and a DL2; and using the received information to schedule at least one transmission or at least one reception in accordance with the at least one RSP. A program storage device as in the previous, wherein the machine comprises the RN or the EN. A program storage device as in any previous, further comprising one or more additional aspects of the exemplary embodiments of the invention as described elsewhere herein.

(8) In another non-limiting, exemplary embodiment, an apparatus comprising: a receiver configured to receive information indicative of at least one relay switch point (RSP) or indicative of a pattern comprising the at least one RSP, wherein the information is received within a communication system that at least partially utilizes a time division communication link between a source node (SN) and an end node (EN) via an intermediate relay node (RN), wherein resources for the time division communication link are allocated according to a resource allocation comprising a plurality of time intervals, wherein each time interval corresponds to one of a first uplink portion (ULl) for communication from the EN to the RN, a second uplink portion (UL2) for communication from the RN to the SN, a first downlink portion (DLl) for communication from the SN to the RN or a second downlink portion (DL2) for communication from the RN to the EN, wherein the at least one RSP corresponds to at least one of a first transition between an ULl and an UL2 or a second transition between a DL 1 and a DL2 ; and a processor configured to use the received information to schedule at least one transmission or at least one reception in accordance with the at least one RSP.

An apparatus as in any previous, wherein the apparatus comprises the RN or the EN. An apparatus as in any previous, further comprising one or more additional aspects of the exemplary embodiments of the invention as described elsewhere herein.

(9) In another non-limiting, exemplary embodiment, an apparatus comprising: means for receiving information indicative of at least one relay switch point (RSP) or indicative of a pattern comprising the at least one RSP, wherein the information is received within a communication system that at least partially utilizes a time division communication link between a source node (SN) and an end node (EN) via an intermediate relay node (RN), wherein resources for the time division communication link are allocated according to a resource allocation comprising a plurality of time intervals, wherein each time interval corresponds to one of a first uplink portion (ULl) for communication from the EN to the RN, a second uplink portion (UL2) for communication from the RN to the SN, a first downlink portion (DLl) for communication from the SN to the RN or a second downlink portion (DL2) for communication from the RN to the EN, wherein the at least one RSP corresponds to at least one of a first transition between an ULl and an UL2 or a second transition between a DLl and a DL2; and means for using the received information to schedule at least one transmission or at least one reception in accordance with the at least one RSP.

An apparatus as in the previous, wherein the means for receiving comprises a receiver and the means for using comprises at least one processor. An apparatus as in any previous, wherein the apparatus comprises the RN or the EN. An apparatus as in any previous, further comprising one or more additional aspects of the exemplary embodiments of the invention as described elsewhere herein.

(10) In another non-limiting, exemplary embodiment, an apparatus comprising: receiving circuitry configured to receive information indicative of at least one relay switch point (RSP) or indicative of a pattern comprising the at least one RSP, wherein the information is received within a communication system that at least partially utilizes a time division communication link between a source node (SN) and an end node (EN) via an intermediate relay node (RN), wherein resources for the time division communication link are allocated according to a resource allocation comprising a plurality of time intervals, wherein each time interval corresponds to one of a first uplink portion (ULl) for communication from the EN to the RN, a second uplink portion (UL2) for communication from the RN to the SN, a first downlink portion (DLl) for communication from the SN to the RN or a second downlink portion (DL2) for communication from the RN to the EN, wherein the at least one RSP corresponds to at least one of a first transition between an ULl and an UL2 or a second transition between a DLl and a DL2; and processing circuitry configured to use the received information to schedule at least one transmission or at least one reception in accordance with the at least one RSP.

The exemplary embodiments of the invention, as discussed above and as particularly described with respect to exemplary methods, may be implemented as a computer program product comprising program instructions embodied on a tangible computer- readable medium. Execution of the program instructions results in operations comprising steps of utilizing the exemplary embodiments or steps of the method.

The exemplary embodiments of the invention, as discussed above and as particularly described with respect to exemplary methods, may be implemented in conjunction with a program storage device readable by a machine, tangibly embodying a program of instructions executable by the machine for performing operations. The operations comprise steps of utilizing the exemplary embodiments or steps of the method.

It should be noted that the terms "connected," "coupled," or any variant thereof, mean any connection or coupling, either direct or indirect, between two or more elements, and may encompass the presence of one or more intermediate elements between two elements that are "connected" or "coupled" together. The coupling or connection between the elements can be physical, logical, or a combination thereof. As employed herein two elements may be considered to be "connected" or "coupled" together by the use of one or more wires, cables and/or printed electrical connections, as well as by the use of electromagnetic energy, such as electromagnetic energy having wavelengths in the radio frequency region, the microwave region and the optical (both visible and invisible) region, as several non-limiting and non-exhaustive examples.

While the exemplary embodiments have been described above in the context of the TD- SCDMA system, it should be appreciated that the exemplary embodiments of this invention are not limited for use with only this one particular type of wireless communication system, and that they may be used to advantage in other wireless communication systems, particularly ones utilizing a time division communication link.

As a non-limiting example, exemplary embodiments of the invention may be utilized within an E-UTRAN or, in particular, within a LTE-TDD system. The E-UTRAN specification will support the use of relay nodes. In addition, the basic frame structure for LTE-TDD, for example, starting with the DL subframe, will likely support use of the exemplary embodiments of the invention.

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

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

Programs, such as those provided by Synopsys, Inc. of Mountain View, California and Cadence Design, of San Jose, California automatically route conductors and locate components on a semiconductor chip using well established rules of design as well as libraries of pre-stored design modules. Once the design for a semiconductor circuit has been completed, the resultant design, in a standardized electronic format (e.g., Opus, GDSII, or the like) may be transmitted to a semiconductor fabrication facility or "fab" for fabrication.

The foregoing description has provided by way of exemplary and non-limiting examples a full and informative description of the invention. However, various modifications and adaptations may become apparent to those skilled in the relevant arts in view of the foregoing description, when read in conjunction with the accompanying drawings and the appended claims. However, all such and similar modifications of the teachings of this invention will still fall within the scope of this invention.

As one example, while shown in FIGS. 5-7 with reference to a certain arrangement and number of resources (e.g., the frame structure, the number of subframes, presence of DwPTS, GP and UpPTS, order and arrangement of the same), the exemplary embodiments of the invention may be utilized with any suitable arrangement and/or number of resources. For example, although shown in FIGS.5-7 with seven different UL and DL blocks, the exemplary embodiments may be implemented in conjunction with a lesser or greater number of UL and DL blocks.

Furthermore, some of the features of the preferred embodiments of this invention could be used to advantage without the corresponding use of other features. As such, the foregoing description should be considered as merely illustrative of the principles of the invention, and not in limitation thereof.

Claims

CLAIMSWhat is claimed is:

1. A method comprising: identifying, based on a resource allocation, at least one relay switch point, wherein the resource allocation is for a time division communication link between an access node and an end node via an intermediate relay node in a communication system, wherein the resource allocation comprises a plurality of time intervals, wherein each time interval corresponds to one of a first uplink portion for communication from the end node to the relay node, a second uplink portion for communication from the relay node to the access node, a first downlink portion for communication from the access node to the relay node or a second downlink portion for communication from the relay node to the end node, wherein the at least one relay switch point corresponds to at least one of a first transition between a first uplink portion and a second uplink portion or a second transition between a first downlink portion and a second downlink portion; and signaling information indicative of the at least one relay switch point or indicative of a pattern comprising the at least one relay switch point from the access node towards the relay node.

2. A method as in claim 1 , wherein signaling comprises broadcasting at least one

3. A method as in claim 1 or 2, wherein the communication system comprises a time division synchronous code division multiple access system.

4. A method as in any one of claims 1 -3 , wherein the method is implemented by the access node.

5. A method as in any one of claims 1-4, wherein the method is implemented by a computer program.

6. An apparatus comprising: means for identifying, based on a resource allocation, at least one relay switch point, wherein the resource allocation is for a time division communication link between the apparatus and an end node via an intermediate relay node in a communication system, wherein the resource allocation comprises a plurality of time intervals, wherein each time interval corresponds to one of a first uplink portion for communication from the end node to the relay node, a second uplink portion for communication from the relay node to the apparatus, a first downlink portion for communication from the apparatus to the relay node or a second downlink portion for communication from the relay node to the end node, wherein the at least one relay switch point corresponds to at least one of a first transition between a first uplink portion and a second uplink portion or a second transition between a first downlink portion and a second downlink portion; and means for signaling information indicative of the at least one relay switch point or indicative of a pattern comprising the at least one relay switch point from the apparatus towards the relay node.

7. An apparatus as in claim 6, wherein signaling the information by the means for signaling comprises broadcasting at least one message comprising the information.

8. An apparatus as in claim 6 or 7, wherein the time division communication link comprises a multi-carrier link and wherein the means for signaling is further for signaling the information from the apparatus towards at least one of the relay node or the end node.

9. An apparatus as in any one of claims 6-8, wherein the communication system comprises a time division synchronous code division multiple access system.

10. An apparatus as in any one of claims 6-9, wherein the apparatus comprises an access node within the communication system.

11. A method comprising: receiving information indicative of at least one relay switch point or indicative of a pattern comprising the at least one relay switch point, wherein the information is received within a communication system that at least partially utilizes a time division communication link between an access node and an end node via an intermediate relay node, wherein resources for the time division communication link are allocated according to a resource allocation comprising a plurality of time intervals, wherein each time interval corresponds to one of a first uplink portion for communication from the end node to the relay node, a second uplink portion for communication from the relay node to the access node, a first downlink portion for communication from the access node to the relay node or a second downlink portion for communication from the relay node to the end node, wherein the at least one relay switch point corresponds to at least one of a first transition between a first uplink portion and a second uplink portion or a second transition between a first downlink portion and a second downlink portion; and using the received information to schedule at least one transmission or at least one reception in accordance with the at least one relay switch point.

12. A method as in claim 11 , wherein the received information comprises a broadcast transmission.

13. A method as in claim 11 or 12, wherein the communication system comprises a time division synchronous code division multiple access system.

14. A method as in any one of claims 11-13, wherein the method is implemented by at least one of the relay node or the end node.

15. A method as in any one of claims 11-14, wherein the method is implemented by a computer program.

16. An apparatus comprising: means for receiving information indicative of at least one relay switch point or indicative of a pattern comprising the at least one relay switch point, wherein the information is received within a communication system that at least partially utilizes a time division communication link between a source node and an end node via an intermediate relay node, wherein resources for the time division communication link are allocated according to a resource allocation comprising a plurality of time intervals, wherein each time interval corresponds to one of a first uplink portion for communication from the end node to the relay node, a second uplink portion for communication from the relay node to the source node, a first downlink portion for communication from the source node to the relay node or a second downlink portion for communication from the relay node to the end node, wherein the at least one relay switch point corresponds to at least one of a first transition between a first uplink portion and a second uplink portion or a second transition between a first downlink portion and a second downlink portion; and means ±or using tnc rεceivεu iuiomiation to scncuUie at ieast one transmission or at least one reception in accordance with the at least one relay switch point.

17. An apparatus as in claim 16, wherein the received information comprises a broadcast transmission.

18. An apparatus as in claim 16 or 17, wherein the received information is indicative of the pattern comprising the at least one relay switch point and wherein the pattern is known in advance by at least one of the relay node or the end node.

19. An apparatus as in any one of claims 16-18, wherein the communication system comprises a time division synchronous code division multiple access system.

20. An apparatus as in any one of claims 16-19, wherein the apparatus comprises a mobile station or a relay node.