WO2014087556A1

WO2014087556A1 - Network access

Info

Publication number: WO2014087556A1
Application number: PCT/JP2013/004649
Authority: WO
Inventors: Lanto Rakotoharison; Caroline Jactat; Benoit LECROART
Original assignee: Nec Corporation
Priority date: 2012-12-07
Filing date: 2013-07-31
Publication date: 2014-06-12
Also published as: GB2508646A

Abstract

There is provided a mechanism within a mobile radio communications network whereby a User Equipment (UE) device (8), so-called UE Target device, can successfully pursue an initial access procedure to a node (2) of a Radio Access Network (4) but in a manner where such procedure is relayed by way of a further UE device (6) serving as a UE Relay. Initial access signalling content is delivered between the node (2) and the UEs (6, 8) so as to provide for pre-configuration of the further UE (6) as a UE relay, and between the UE Target device (8) and the UE Relay, within Radio Resource Control (RRC) messaging which can comprise enhanced current RRC messages, or specific new RRC messages. In either case the network node (2) can then communicate via the UE Relay (6) with a UE Target (8) which may not otherwise be under its coverage.

Description

NETWORK ACCESS

The present invention relates to User Equipment (UE) network access procedures in a mobile radio communications network and system, and including signal relaying.

In a 3^rd Generation Partnership Project (3GPP) Long Term Evolution (LTE) network, the evolved NodeB (eNB) network nodes forming part of the Radio Access Network serve to transmit/receive data and signalling between the Core Network (CN) and the UE devices which are under its radio cell coverage. The UEs also transmit/receive data and/or signalling to/from the eNB whenever a communication session is required (e.g. to register, update registration, establish a data session or a voice call).

However, due to various factors, such as environmental characteristics, path loss, and power limitation, the cell coverage may be limited or there may be some regions where the signals from the eNB cannot be decoded by the UEs. In addition, since an eNB serves as a focus for the communication signalling, its available resources may become limited or insufficient. Consequently there may be fewer services available for users and the ongoing communication/applications may suffer latency issues.

In an attempt to deal with some of the above problems and limitations, discussions within 3GPP Groups have suggested the introduction of Relay Node entities in the form of Relay Base Stations. In such an arrangement, rather than having the UEs operating in direct communication with the eNB, data and/or signalling from the UE for example passes via one of the Relay Nodes before reaching the target node generally referred to as a Donor eNB or DeNB. Conversely, for eNB to UE communication, transmitted data and/or signalling can pass through a Relay Node before reaching the UE.

Such a relaying function is considered attractive for improving the cell coverage and/or providing the network with offloading alternatives.

3GPP mobile standardization discussions have also covered aspects of "nearby-device" communication in the context of Public Safety scenarios as part of the ProSe study started in 2011. In the context of public safety, the communication between nearby device is expected to allow the users to fulfill their mission even when there is a lack of network infrastructure coverage. The use of device as relay for other device is also expected in public safety situation, in order to extend the network coverage either at the edge of a cell, or when a public safety user is in a coverage hole inside a building and has to rely on nearby devices under coverage to access to the network infrastructure.

Also, from WO 2011/111229, it is known to provide a mobile communication system with relay control and employing a relay station for relaying communication signals between a base station and mobile station.

PTL 1: International Patent Publication No. 2011/111229

However, there is a problem that known said procedures, systems and devices have operational limitations as to the manner of messaging between the stations and the relay configuration.

The invention seeks to provide for a network access relay procedure and related systems and devices having advantages over known said procedures, systems and devices.

According to one aspect of the present invention, there is provided a method of enabling an initial access procedure for a first UE device to a node of a mobile radio communications network via a second UE device, and including the step of conveying initial access content by way of Radio Resource Control signalling within the network.

The invention provides an advantageous mechanism whereby the network can communicate with a UE device, hereafter referred to as a Target UE or UE-T, by way of another UE device, hereafter referred to as a Relay UE or UE-R, wherein the UE-T need not be under the network's coverage, for initial access purposes. This can also provide control of the initial access parameters to the network.

While the MAC (Media Access Control) and Physical parameters needed for the UE-T RACH procedure could be conveyed into the UE-R's MAC and Physical parameters, this would lead to signalling overheads for the relevant protocols, and the present invention does not exhibit such disadvantages and limitations. Also, through use of the RRC protocol according to an embodiment of the present invention, improved reliability of transmission of the RRC messages can be achieved and which would not arise with MAC nor PHY (Physical layer) protolcols.

The said Radio Resource Control signalling conveying the initial access content can be arranged for preconfiguring the second UE device as an UE-R device, and this can include the step of broadcasting initial access content from the second UE device to the first UE device.

It will be appreciated that the initial access content is not restricted but can advantageously include at least part of System Information Broadcast parameters.

As another option, rather than initial broadcast of the content, it can be stored in the said second UE for a subsequent initial access procedure in the said first UE.

In another embodiment of the invention, the initial access content comprises second UE device information provided from the second UE device to the first UE device for the said initial access procedure.

The said second UE device information can comprise local information in the form of at least one of cell selection information, frequency band/carrier signalling, and further can be provided from the said second UE device along with information delivered from the network to the said first UE device.

Alternatively, the second UE device can be arranged to supersede received network broadcast information with the said local information prior to delivery to the said second UE device.

Yet further, the initial access content can comprise first UE device initial access parameters, and provided within an additional Radio Resource Control message conveyed from the said second UE device to the network.

In particular, the said initial access content can include MAC content.
In one example, the said initial access content can comprise a Radio Resource Control message enhanced with an additional Information Element including the said content.

Alternatively, the said initial access content can comprise an additional Radio Resource Control message.

The method can be performed so that the said second UE device can handle the complete Random Access Channel procedure of the said first UE device, or alternatively so that the said second UE device relays at least part of a Random Access Channel procedure of the said first UE device to the network.

According to another aspect of the present invention, there is provided a mobile radio communications network UE device, arranged to receive initial access content by way of Radio Resource Control signalling within the network, for pre-configuration as a UE-Relay device (UE-R) for relaying initial access content between a UE-Target device (UE-T) and the network.

According to yet another aspect of the present invention there is provided a mobile radio communication network UE-Target device (UE-T), arranged to exchange initial access content by way of radio resource control signalling with a UE-Relay device (UE-R) within the network, for providing initial access of the UE-Target device (UE-T) to the network.

As will be appreciated, a particular aspect of the invention focuses on the Random Access Channel (RACH) procedure and how to achieve this by way of a
a UE-Relay device (UE-R).

From the more detailed discussion that follows, the invention can provide for new RRC (Radio Resource Control) Information Elements (IE), or indeed a new RRC message, allowing the RAN, via an eNB and dedicated signalling with information to be broadcast or stored, to configure the UE-R. The UE-R can then serve to relay a target UE's initial access procedure, such as its Random Access procedure, to the RAN.

Such new RRC signalling can also allow a UE-R to broadcast initial access information as received from the RAN for relayed UEs; broadcast some initial access information that would supersede that of the RAN; and to transfer relayed UEs initial access related message/information to/from the RAN's eNB.

In this manner, a target UE can gain initial access to the network via the UE-R.

The invention is described further hereinafter, by way of example only, with reference to the accompanying drawings in which:

Fig. 1 is a schematic representation of connections of mobile radio communication UE devices within a mobile radio communications network according to an embodiment of the present invention;

Fig.2 is a signalling diagram illustrating an initial access procedure for UE within a E-UTRAN environment and as known in the art;

Fig. 3 is a signalling diagram relating to preconfiguration of a UE-R device according to one embodiment of the present invention;

Fig. 4 is a signalling diagram relating to preconfiguration of a UE-R device according to another embodiment of the present invention;

Fig. 5 is a diagram of signalling for configuration of a UE-R device in an embodiment of the present invention; and

Fig. 6 is a diagram of signalling of a UE-R relaying initial access messaging in another aspect of the invention.

Turning first to Fig.1, there is illustrated, in a schematic form, network connectivity according to an embodiment of the present invention but without reference to the Core Network (CN). Accordingly, there is illustrated a node 2 of a Radio Access Network (RAN) 4 and first and second mobile radio communication devices, such as User Equipment (UE) 6 and User Equipment (UE) 8. While UE 6 is under coverage of the RAN 4 for the initial access purposes, this need not be the case for UE 8. However, and as is described in further detail below according to one particular embodiment of the present invention, the UE 6 can be configured as a relay device UE-R by which communication between the RAN 4 and the UE 8, which can then be identified as a target device UE-T, can be achieved as required.

By way of initial background however, reference is made to Fig. 2 which illustrates the messaging arising in an initial access procedure for a UE device within a E-UTRAN cell.

Fig. 2 is a schematic representation of a cellular network environment 10 of a mobile communications system in which a UE device 12, such as for example a mobile phone handset is to establish connection with a network node eNB 14 of the system's Radio Access Network (RAN), the full RAN and Core Network not being represented in the figure.

Within the network environment System Information Block (SIB) messaging 16 originates from the eNB 14 and can be received by UE12. Until such time as access by the UE 12 to the RAN is made, and the connection established, the RAN and its eNB 14 are unaware of the existence of the UE 12 within the cell. In order to start the connection between the UE 12 and the eNB 14 , the UE 12 initiates a random access procedure by way of a Random Access Channel (RACH) so that it becomes visible within the cell. The RACH procedure comprises Physical RACH (PRACH) preamble signalling 18 from the UE 12 and a random access response 20 from the eNB. The transmission of the preamble 18 is governed by a Preamble Transmission Counter and also generates a Random Access Radio Network Temporary Identifier (RA-RNTI). The PRACH preamble and "RA config" parameters are of course known by the UE 12, and the "RA config" known for each PRACH-Configuration broadcast. The eNB 14 computes the RA-RNTI further to the preamble 18 reception and within the response 20 includes RA radio information such as a RA preamble identifier, temporary Cell-RNTI, Uplink grant and Timing Advance parameters.

Once the RACH procedure represented by signalling 18, 20 have been completed, the UE 12 sends a Radio Resource Control (RRC) ConnectionRequest 22 to which the eNB 14 responds with contention resolution signalling 24 and subsequently a RRC ConnectionSetup message 26. If the UE 12 detects successful completion of the RA procedure, the temporary nature of the C-RNTI is promoted to full C-RNTI. If the detection of such success does not occur within a contention resolution timer range related to the signalling 24, the procedure returns to the RACH stage with the UE 12 sending a new PRACH preamble.

Confirmation that the initial access procedure has been successfully completed is sent by way of an appropriate confirmatory message 28 from the UE 12.

The following discussion of particular embodiments of the present invention focus on the RACH

procedure comprising messages

18 and 20 of the known initial access procedure of Fig. 2, so as to provide means for performing an appropriate RACH procedure for a UE employing a relayed connection to the RAN by way of a UE-R.

Turning now to Figs. 3 and 4, there are illustrated variants of preconfiguration procedures for a UE-R from the RAN for the broadcast of information for the UE-T. Two implementations are illustrated regarding the local information that the UE-R can provide to the UE-T. In the example of Fig. 3 UE-R broadcast System Information Broadcast (SIB) requested by the eNB 32 in the signal 36 to the UE-T. In the alternative of Fig. 4 UE-R broadcast SIB requested by the eNB 32 in the signal 36 where some parameters included in the SIB are superseded by UE-R.

Turning first to Fig. 3, there is provided a schematic illustration of a network environment in which a UE to be configured as a relaying UE, UE-R 30, of the invention is located within the cell of eNB 32, and which UE-R 30 can further communicate with a target UE to be relayed, UE-T 34. The eNB 32 provides the minimum preconfiguration for relaying purpose to the UE-R upon e.g. knowing that UE-R has relaying capabilities and UE-R moves onto the cell, and so, in order to achieve this novel aspect of the invention in this example, sends a signal 36 comprising RRC_PreConfigurationInfoForRelayingPurpose or RRC_ConnectionReconfiguration orRRC_HandoverCommand containing relayedUEContainerInfoToBeBroadcast IE including SIB1 or partial SIB1, SIB2 or partial SIB2, other SIBs (e.g. SIB10/11 related to warning notifications) and maximumInterBroadcastingEvents Periodicity. The SIBs noted are those that the eNB 32 requests that the UE-R 30 broadcast towards the UE-T 34. Also, the maximum periodicity parameter is that which the eNB 32 requests UE-R 34 to respect between two consecutive broadcasting events towards the UE-T 34.

Subsequently the UE-R 30 forwards SIBs 38 to the UE-T 34, and which can comprise the eNB's SIBs.

In this manner, UE-R 30 preconfiguration for UE-T initial access can be achieved.

In Fig. 4, there is illustrated a signalling procedure for UE-R 30 preconfiguration for UE-T 34 initial access achieved where some parameters included in the SIB requested by the eNB in signaling 40 are superseded by UE-R 30. Similar preconfiguration signalling 40 to that of Fig. 3 is sent from the eNB 32 to the UE-R 30 and with the same SIBs and parameters of maximum periodicity. In this case however, the subsequent signalling 42 from the UE-R 30 to the UE-T 34 comprise SIBs including local access information and whereby, according to this example of the invention, the UE-R 30 has replaced RAN SIBs with SIBs local information to UE-T 34.

The following Table below illustrates SIB1/2/10/11 parameters which can be requested using RAN configuration to be broadcast by the UE-R and as illustrated in Figs. 3 and 4.

Certain of the parameters can be modified locally by the UE-R and as such supersede those values provided by RAN in the UE-T as discussed further below.

As noted, certain of the above parameters can be modified locally by the UE-R 30. For example, within the SIB1 information, the "Q-RxLevMin" parameter can be modified by UE-R for e.g. interference mitigation purpose and the "q-RxLevMinOffset" parameter can be modified by the UE-R for e.g. interference mitigation purpose. The "p-Max" parameter can be modified by the UE-R for e.g. interference limitation purpose, and the "freqBandIndicator" can be modified by the UE-R in case of e.g. dedicated frequency band for relaying or interference limitation purposes.

Within the SIB2 information, the "uplinkPowerControlCommon" parameter can be modified by the UE-R in case of e.g. interference mitigation purpose, the "ul-CarrierFreq" parameter can be modified by the UE-R in case of e.g. dedicated UL frequency band for relaying or interference mitigation purpose. The "ul-Bandwidth" parameter can be modified by the UE-R in case of e.g. interference limitation purposes, as indeed can the "additionalSpectrumEmission" parameter. Also, the "UETimersAndConstants" can be arranged for the UE-R to configure the timers and constants related to the RRC Connection(Re)Establishment, constants related to physical layer synchronization.

From the above UE-R preconfiguration for UE-T initial access, two possible options can be covered and determined by the capability of the UE-R to handle the actual UE-T RACH or not.

According to the device implementation, the UE-R may be arranged to handle any UE-T initial access procedure i.e. similarly to initial access procedure handling by the RAN, or alternatively to only transfer UE-T initial access procedure message to the RAN.
Other parameters can also to be considered such as:
-Delay to access to network, such as by taking UE-R to eNB and UE-T to UE-R ranges into account or by data priority;
-Cell planning, such as by cell loads and capacities; and
-input information for the RAN to decide to configure UE-R to handle UE-T RACH or not.

A scenario in which the UE-R is itself able to execute the full UE-T RACH is discussed further with reference to Fig. 5 and which concerns a dedicated configuration to the UE-R to handle fully the Random Access procedure.

In this scenario reference is again made to a UE-R 30, eNB 32 and UE-T 34, it being noted that the eNB will identify that UE-R can handle UE-T RACH. For this purpose, eNB provides all necessary configuration information to UE-R. Initial signalling 44 is sent from the eNB 32 and comprises RRCPreConfigurationInfoRelayingPurpose or RRCConnectionReconfiguration or HandoverCommand including relayedUEContainerInfoDedicated IE with Relay C-RNTI values range".

The UE-R 30 can store the dedicated information for further UE-T RACH, and, subsequent to RA-RNTI generation of the UE-T 34, the UE-R 30 receives PRACH preamble signalling 46 and aims to compute the RA-RNTI.

A Random Access Response message 48 is then sent from the UE-R 30 to the UE-T 34 and which can include RA radio info includes (RA preamble ID, temp C-RNTI (one of the previously configured C-RNTI values), UL grant, TA). UL grant and TA are computed from channel quality information between 2 UEs, by way of signalling 50 and the same as in State of Art where UE-R performs eNB related actions.

As noted, it is considered that the RAN knows that the UE-R is able to handle initial access procedure i.e. compute necessary parameters for Random Access procedure such as temporary C-RNTI, Uplink grant and Timing Advance. UET sends Random Access preambles to UE-R based on SIB broadcast parameters received from UE-R (as shown in Fig. 2).

UE-R is configured by the eNB via new RRC messages (PreconfigurationForRelayingPurpose) or enhanced RRC messages (RRCConnectionReconfiguration or HandoverCommand (i.e. RRCConnectionReconfiguration including MobilityControlInformation IE)) with relayedUEContainerInfoDedicated IE including Relay C-RNTI values range which will be further used when UE-T performs the RA procedure.

Those C-RNTI values are dedicated C-RNTI values for relaying purpose configured by the network.

Next, a scenario in which the UE-R is not able to handle the full UE-T RACH procedure is discussed with reference to Fig. 6.

In this scenario, it is considered a precondition that the UE-R 30 is connected to eNB 32. The procedure commences with generation of a RA-RNTI at the UE-T 34 and the sending by the UE-T 34 of a PRACH Preamble message 52. As a novel feature of this example of the present invention, the UE-R 30 then sends a RRCRelayUEULInfoTransfer including relayedUEContainerInfoDedicated IE which contains PhyParams: UE-T physical parameters detected message 54 to the eNB 32 which in turn creates a UE-T ID RRC context. The physical parameters can be UE-T RA-RNTI or time and frequency parameters used further by the eNB to compute UE-T RA-RNTI or Preambles sent by UE-T for RA procedure.

A "RRCConnectionReconfiguration (cf. configuration of SRB used for relay purpose (out of scope))" message 56 is then sent to the UE-R 30, followed by another novel feature of this example of the invention comprising the RRCRelayUEDLInfoTransfer containing relayedUEContainerInfoDedicated IE in which MacParams are Radio Access Response containing UE-T RA radio info message 58. The RA radio info of this message includes at least RA preamble ID, temp C-RNTI to be used by UE-T for further access.

A "Random Access Response" message 60 is then sent from the UE-R 30 to the UE-T 34 and "RRCConnectionRequest" signal 62 relayed as 62A, 62B via the UE-R 30.

At reception of the Random Access preamble from the UE-T and as sent based on SIB parameters broadcast by UE-R, the random access message is transferred to the eNB in new RRC UpLink messages (RelayUEULInfoTransfer) including new IEs (relayedUEContainerInfoDedicated).

The UE-T radio identifier used for random access, i.e. the RA-RNTI, will be further decoded by the eNB within the new container and random access response parameters (e.g. UE-T temporary C-RNTI for further RRC connected state) are generated and transferred by UE-R in new RRC downlink messages (RelayUEDLInfoTransfer) including new IEs (relayedUEContainerInfoDedicated). The IE contains MAC parameters used for Random Access Response.

As will therefore be appreciated, the present invention can provide for parameters and messages related to UE-T initial access to be conveyed into RRC messages or container Information Elements (IEs).

In one aspect they are related to Relay UE preconfiguration by the Network to allow for UE-T initial access.

RRC messages can be arranged to include new IEs made up of parameters used for relaying purpose provided by the network. Such IEs can be RelayUEContainerInfoDedicated which can be retained at the UE-R for further UE-T initial access. Alternatively they can be embodied as RelayUEContainerInfoToBeBroadcast messages which are broadcast to the UE-T by the UE-R.

In further detail of such examples, the RelayUEContainerInfoToBeBroadcast IE can include part or whole of the System Information Broadcast parameters available in the network. Also this RelayUEContainerInfoToBeBroadcast IE can include maximumInterBroadcastingEventsPeriodicity information which is the maximum periodicity that eNB requests UE-R to respect between two consecutive broadcasting events towards UE-T. The RelayUEContainerInfoDedicated IE can include Cell Radio Network Temporary Identifier (C-RNTI) values range for relaying purpose. A new RRC message, such as RRCPreconfigurationInfoForRelaying, or an existing RRC message, such as RRCConnectionReconfiguration, can be used to convey the RelayUEContainerInfoDedicated IE or the RelayUEContainerInfoToBeBroadcast IE.

In a further aspect they are related to UE-R information provided by UE-R to UE-T for initial access. Here the UE-R can provide local information such as cell selection information, frequency band/carrier via broadcast signalling to the UE-T. Beforehand the RAN can configure the type of information such as cell selection information, frequency band/carrier that UE-R should set and provide to UE-T. In one arrangement, if the UE-R provides such information along with that received from RAN to UE-T, then such information can supersede that provided by the RAN in the UE-T. Alternatively the UE-R can supersede received RAN broadcast information with aforementioned information.

In yet a further aspect, the parameters and messages can be related to UE-T initial access. The RelayUEContainerInfoDedicated IE can include physical and MAC parameters related to UE-T initial access. In one example, a new RRC message, such as RRCRelayUEULInfoTransfer in which the UE-R includes UE-T initial access parameters, is conveyed from the UE-R to the RAN. Also, a new RRC message, such as RRCRelayUEDLInfoTransfer in which RAN includes MAC Random Access Response or MAC parameters is conveyed from the RAN to the UE-R. The latter serves to retrieve and forward the MAC Random Access Response to the UET and the UE-R can retrieve and build MAC message for the UE-T including the MAC parameters received from the RAN.

It should therefore be appreciated that the invention provides for a mechanism within a mobile radio communications network whereby a User Equipment (UE) device, so-called UET device, can successfully pursue an initial access procedure to a node of the network but in a manner where such procedure is relayed by way of a further UE device serving as a UE-R. Initial access signalling content is delivered between the node and the UEs so as to provide for pre-configuration of the further UE as a UE-R, and between the UETt device and the UE-R-, within Radio Resource Control (RRC) messaging which can comprise enhanced current RRC messages, or specific new RRC messages. In either case the network node can then communicate via the UE-R with a UE-T which may not otherwise be under its coverage.

This application is based upon and claims the benefit of priority from United Kingdom Patent Application No. 1222058.8, filed on December 7, 2012, the disclosure of which is incorporated herein in its entirety by reference.

2 NODE
4 RADIO ACCESS NETWORK
6 USER EQUIPMENT
8 USER EQUIPMENT
12 USER EQUIPMENT
14 eNB
30 UE-R
32 eNB
34 UE-T

Claims

A method of enabling an initial access procedure for a first UE device to a node of a mobile radio communications network via a second UE device, and including the step of conveying initial access content by way of Radio Resource Control signalling within the network.
A method as claimed in Claim 1, wherein the said Radio Resource Control signalling conveying the initial access content is arranged for preconfiguring the second UE device with parameters useful for relaying purposes.
A method as claimed in Claim 2, and including the step of broadcasting initial access content from the second UE device to the first UE device.
A method as claimed in a Claim 3, wherein the initial access content includes at least System Information Broadcast parameters.
A method as claimed in Claim 3 or 4, wherein the initial access content includes periodicity information from the node to the second UE device for discerning between broadcast events towards the first UE device.
A method as claimed in Claim 2 or 3, and including the step of storing initial access content in the said second UE for a subsequent initial access procedure in the said first UE.
A method as claimed in Claim 6, wherein the initial access content includes Cell Radio Network Temporary Identifier values.
A method as claimed in any one of Claims 2 to 7, wherein the said second UE device pre-configuration from the network allows at least detection of dedicated Random-Access preambles of the first UE device at the said second UE device.
A method as claimed in any one of Claims 1 to 8, wherein the initial access content comprises information from second UE device provided from the second UE device to the first UE device for the said initial access procedure.
A method as claimed in Claim 9, wherein the said second UE device information comprises local information in the form of at least one of cell selection information, frequency band/carrier signalling, RACH configuration parameters.
A method as claimed in Claim 10, wherein the said local information is requested to be configured from second UE device by the node for first UE device said initial access.
A method as claimed in Claim 10, wherein the said local information is provided from the said second UE device along with information delivered from the network to the said first UE device.
A method as claimed in Claim 10, wherein the second UE device supersedes received network broadcast information with the said local information prior to delivery to the said first UE device.
A method as claimed in any one or more of Claims 1 to 13, wherein the initial access content comprises first UE device initial access parameters.
A method as claimed in Claim 14, wherein the initial access content is provided within an additional Radio Resource Control message conveyed from the said second UE device to the network.
A method as claimed in Claim 15, wherein the said initial access content includes MAC content.
A method as claimed in Claim 14, wherein the said initial access content includes MAC content delivered from the network to the said second UE device.
A method as claimed in Claim 17, wherein the said MAC content comprises at least one of MAC random access response messaging or MAC parameters.
A method as claimed in any one of Claims 15 to 18, and including the step of the said second UE device forming a MAC message to the said first UE device and including MAC parameters received from the network.
A method as claimed in any one of Claims 1 to 19, wherein said initial access content comprises a Radio Resource Control message enhanced with an additional Information Element including the said content.
A method as claimed in any one of Claims 1 to 19, wherein the said initial access content comprises an additional Radio Resource Control message.
A method as claimed in any one of Claims 1 to 21, wherein the said initial access content comprises initial access parameters and messages.
A method as claimed in Claim 22, wherein the said initial access content comprises at least MAC and PHY parameters.
A method as claimed in Claim 22 where PHY parameters comprise time and frequency parameters used to compute the Random Access - Radio Network Temporary Identifier (RA-RNTI) or a Preamble.
A method as claimed in any one of Claims 1 to 24, wherein the said second UE device handles the complete Random Access Channel procedure of the said first UE device on behalf of the network.
A method as claimed in Claim 25, wherein the said second UE device performs dedicated configuration for initial access handling of the said first UE device Random Access Channel procedure.
A method as claimed in any one of Claims 1 to 24, and including the step of, in the said second UE device, relaying at least part of a Random Access Channel procedure of the said first UE device to the network.
A mobile radio communications network UE device, arranged to receive initial access content by way of Radio Resource Control signalling within the network, for pre-configuration with parameters useful for relaying purposes for relaying initial access content between a second UE device and the network.
A mobile radio communication network UE device, arranged to exchange initial access content by way of radio resource control signalling with the network, for providing initial access of the mobile radio communication UE device to the network.