ETSI ETS 300 700 ed.1 (1997-03)

SLOVENSKI STANDARD
01-december-2003
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Digital Enhanced Cordless Telecommunications (DECT); Wireless Relay Station (WRS)
Ta slovenski standard je istoveten z: ETS 300 700 Edition 1
ICS:
33.070.30 'LJLWDOQHL]EROMãDQH Digital Enhanced Cordless
EUH]YUYLþQHWHOHNRPXQLNDFLMH Telecommunications (DECT)
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2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN ETS 300 700
TELECOMMUNICATION March 1997
STANDARD
Source: ETSI EP DECT Reference: DE/DECT-050069
ICS: 33.020
Key words: DECT, WRS
Digital Enhanced Cordless Telecommunications (DECT);
Wireless Relay Station (WRS)
ETSI
European Telecommunications Standards Institute
ETSI Secretariat
Postal address: F-06921 Sophia Antipolis CEDEX - FRANCE
Office address: 650 Route des Lucioles - Sophia Antipolis - Valbonne - FRANCE
X.400: c=fr, a=atlas, p=etsi, s=secretariat - Internet: secretariat@etsi.fr
Tel.: +33 4 92 94 42 00 - Fax: +33 4 93 65 47 16
Copyright Notification: No part may be reproduced except as authorized by written permission. The copyright and the
foregoing restriction extend to reproduction in all media.
© European Telecommunications Standards Institute 1997. All rights reserved.

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ETS 300 700: March 1997
Whilst every care has been taken in the preparation and publication of this document, errors in content,
typographical or otherwise, may occur. If you have comments concerning its accuracy, please write to
"ETSI Editing and Committee Support Dept." at the address shown on the title page.

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ETS 300 700: March 1997
Contents
Foreword .7
1 Scope .9
2 Normative references.9
3 Definitions and abbreviations .10
3.1 Definitions .10
3.2 Abbreviations .11
4 Wireless Relay Station (WRS) .12
4.1 Introduction .12
4.2 Description.12
4.2.1 PHL layer functions .13
4.2.2 MAC layer functions .13
4.2.3 Data Link Control (DLC) layer functions.13
4.2.4 NWK layer functions.13
4.2.4.1 Over-the-air maintenance.13
4.2.5 Identities .14
4.3 Services .14
4.4 Procedures.14
4.4.1 PHL layer.14
4.4.2 MAC layer.14
4.4.2.1 Extended fixed part capabilities.14
4.4.2.2 Hop control .14
5 Cordless Radio Fixed Part (CRFP) .15
5.1 Description.15
5.1.1 General.15
5.1.2 Reference model.15
5.1.3 MAC layer functions .15
5.1.3.1 General.15
5.1.3.2 Frame multiplexing structure .16
5.1.3.3 Logical channel mapping.17
5.1.3.4 Quality Control and Flow Control.17
5.1.4 NWK layer functions.17
5.1.5 Identities .18
5.1.5.1 Identities and addressing.18
5.1.5.2 Subscription data.18
5.2 Messages.18
5.2.1 MAC layer control.18
5.3 Procedures.19
5.3.1 MAC layer.19
5.3.1.1 Connection Oriented mode (C/O) procedures at CRFP.19
5.3.1.1.1 Creation of a Relay Multi Bearer
Control (RMBC) .19
5.3.1.1.2 Normal C/O bearer set-up .19
5.3.1.1.3 Dual C/O bearer set-up.20
5.3.1.1.4 C/O connection release .21
5.3.1.1.5 C/O abnormal connection release .22
5.3.1.2 CRFP connection suspend and resume.24
5.3.1.3 C/O bearer handover.25
5.3.2 DLC layer.27
5.3.2.1 Connection handover.27
5.3.2.2 DLC variables .27
5.3.3 NWK layer .28
5.3.4 Security.29

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ETS 300 700: March 1997
5.3.4.1 General . 29
5.3.4.2 CRFP initialization of PT cipher key. 31
5.3.5 Management. 31
5.3.5.1 CRFP MAC modes . 31
5.3.5.2 CRFP states and state transitions . 31
5.4 Example operation of CRFP . 32
5.4.1 Introduction . 32
5.4.2 Example GAP procedures . 32
6 Repeater Part (REP). 32
6.1 Description . 32
6.1.1 General . 32
6.1.2 Reference model . 32
6.1.3 MAC layer functions. 33
6.1.3.1 General . 33
6.1.3.2 Frame multiplexing. 33
6.1.3.2.1 Quality control . 35
6.1.3.2.2 Bearers selection . 36
6.1.3.2.3 Establishment of the double duplex
bearer. 36
6.1.3.2.4 Double simplex bearers . 36
6.1.3.3 Logical channel mapping . 36
6.1.4 DLC functions . 37
6.1.5 NWK layer functions . 37
6.1.6 Management functions . 38
6.1.6.1 Identities and addressing . 38
6.2 Definitions. 38
6.3 Messages. 38
6.3.1 MAC control (Mt). 38
6.4 Procedures. 38
6.4.1 MAC layer . 38
6.4.1.1 C/O connection . 38
6.4.1.1.1 Physical set-up procedure. 38
6.4.1.1.2 Creation of a double duplex bearer. 40
6.4.1.1.3 Mapping procedure . 40
6.4.1.2 REP relayed C/O connection . 41
6.4.1.2.1 IWU . 41
6.4.1.2.2 REP relayed C/O single duplex bearer
set-up . 42
6.4.1.2.3 REP relayed C/O bearer release. 43
6.4.1.2.4 REP relayed C/O bearer handover . 43
6.4.2 DLC layer. 44
6.4.2.1 REP relayed C/O connection handover . 44
6.4.3 Management. 44
6.4.3.1 REP states . 44
6.4.3.2 REP actions and states transitions . 45
6.4.3.2.1 Actions in the Idle_Unlocked and
Active_Unlocked states. 45
6.4.3.2.2 Actions in the Locked state . 45
6.4.3.2.3 Entry into the Active_Idle state. 45
6.4.3.2.4 Actions in the Active_Idle state . 46
6.4.3.2.5 Entry into the Active_Traffic state . 46
6.4.3.2.6 Actions in the Active_Traffic state. 46
6.4.3.3 Channel selection. 46
6.5 Example operation of REP. 47
Annex A (normative): The optional CRFP interface to REP . 55
A.1 Description. 55
A.1.1 General. 55
A.1.2 Frame multiplexing structure. 55
A.2 Messages . 56

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A.2.1 MAC layer .56
A.2.2 Hop control.56
A.3 Procedures.56
A.3.1 MAC layer .56
A.3.2 Channel selection .58
Annex B (normative): ETS 300 175 changes.59
B.1 Modifications to MAC layer specification, ETS 300 175-3.59
B.1.1 Modifications to subclause 7.1.4.59
B.1.2 Modifications to subclause 7.2.3.4.2.60
B.1.3 Modifications to subclause 10.5.1.1.61
B.1.4 Modifications to subclause 10.5.1.2.1.61
B.1.5 Modifications to subclause 10.5.1.3.1.61
B.2 Modifications to NWK layer specification, ETS 300 175-5.61
B.2.1 Modifications to subclause 7.7.18.61
History.62

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ETS 300 700: March 1997
Foreword
This European Telecommunication Standard (ETS) has been produced by the Digital Enhanced Cordless
Telecommunications (DECT) Project of the European Telecommunications Standards Institute (ETSI).
Transposition dates
Date of adoption: 21 February 1997
Date of latest announcement of this ETS (doa): 30 June 1997
Date of latest publication of new National Standard
or endorsement of this ETS (dop/e): 31 December 1997
Date of withdrawal of any conflicting National Standard (dow): 31 December 1997

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ETS 300 700: March 1997
1 Scope
This European Telecommunication Standard (ETS) defines the Digital Enhanced Cordless
Telecommunications (DECT) Wireless Relay Station (WRS). A WRS is an additional building block for the
DECT fixed network.
This ETS defines provisions needed for a controlled and reliable application of the DECT WRS
infrastructure building block. These provisions are not related to any specific profile.
2 Normative references
This ETS incorporates, by dated or undated reference, provisions from other publications. These
normative references are cited at the appropriate places in the text and the publications are listed
hereafter. For dated references, subsequent amendments to or revisions of any of these publications
apply to this ETS only when incorporated in it by amendment or revision. For undated references the latest
edition of the publication referred to applies.
[1] ETS 300 175-1: "Radio Equipment and Systems (RES); Digital European
Cordless Telecommunications (DECT); Common Interface (CI); Part 1:
Overview".
[2] ETS 300 175-2: "Radio Equipment and Systems (RES); Digital Enhanced
Cordless Telecommunications (DECT); Common Interface (CI); Part 2: Physical
layer (PHL)".
[3] ETS 300 175-3: "Radio Equipment and Systems (RES); Digital European
Cordless Telecommunications (DECT); Common Interface (CI); Part 3: Medium
Access Control (MAC) layer".
[4] ETS 300 175-4: "Radio Equipment and Systems (RES); Digital European
Cordless Telecommunications (DECT); Common Interface (CI); Part 4: Data
Link Control (DLC) layer".
[5] ETS 300 175-5: "Radio Equipment and Systems (RES); Digital European
Cordless Telecommunications (DECT); Common Interface (CI); Part 5: Network
(NWK) layer".
[6] ETS 300 175-6: "Radio Equipment and Systems (RES); Digital European
Cordless Telecommunications (DECT); Common Interface (CI); Part 6:
Identities and addressing".
[7] ETS 300 175-7: "Radio Equipment and Systems (RES); Digital European
Cordless Telecommunications (DECT); Common Interface (CI); Part 7: Security
features".
[8] ETS 300 175-8: "Radio Equipment and Systems (RES); Digital European
Cordless Telecommunications (DECT); Common Interface (CI); Part 8: Speech
coding and transmission".
[9] ETR 043: "Radio Equipment and Systems (RES); Digital European Cordless
Telecommunications (DECT); Common interface; Services and facilities
requirements specification".
[10] ETR 246: "Radio Equipment and Systems (RES); Digital European Cordless
Telecommunications (DECT); Application of DECT Wireless Relay Station
(WRS)".
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ETS 300 700: March 1997
3 Definitions and abbreviations
3.1 Definitions
For the purposes of this ETS, the following definitions apply:
Cordless Radio Fixed Part (CRFP): A WRS that provides independent bearer control to a Portable radio
Termination (PT) and Fixed radio Termination (FT) for relayed connections.
Fixed Part (DECT Fixed Part) (FP): A physical grouping that contains all of the elements in the DECT
network between the local network and the DECT air interface.
NOTE 1: A DECT FP contains the logical elements of at least one FT, plus additional
implementation specific elements.
Fixed radio Termination (FT): A logical group of functions that contains all of the DECT processes and
procedures on the fixed side of the DECT air interface.
NOTE 2: A FT only includes elements that are defined in the DECT CI standard. This includes
radio transmission elements together with a selection of layer 2 and layer 3 elements.
Handover: The process of switching a call in progress from one physical channel to another physical
channel. These processes can be internal (see internal handover) or external (see external handover).
NOTE 3: There are two physical forms of handover, intra-cell handover and inter-cell handover.
Intra-cell handover is always internal. Inter-cell handover can be internal or external.
Inter Working Unit (IWU): A unit that is used to interconnect sub networks.
NOTE 4: The IWU contains the inter-working functions necessary to support the required sub
network inter-working.
Medium Access Control (MAC) Connection (CONNECTION): An association between one source MAC
Multi-Bearer Control (MBC) entity and one destination MAC MBC entity. This provides a set of related
MAC services (a set of logical channels), and it can involve one or more underlying MAC bearers.
Portable Part (DECT Portable Part) (PP): A physical grouping that contains all elements between the
user and the DECT air interface. PP is a generic term that may describe one or several physical pieces.
NOTE 5: A DECT PP is logically divided into one PT plus one or more Portable Applications
(PAs).
Portable radio Termination (PT): A logical group of functions that contains all of the DECT processes
and procedures on the portable side of the DECT air interface.
NOTE 6: A PT only includes elements that are defined in the DECT CI standard. This includes
radio transmission elements (layer 1) together with a selection of layer 2 and layer 3
elements.
Radio Fixed Part (RFP): One physical sub-group of a FP that contains all the radio end points (one or
more) that are connected to a single system of antennas.
Repeater Part (REP): A WRS which relay the information within the half frame time interval.
Wireless Relay Station (WRS): A physical grouping that combines elements of both PTs and FTs to
relay information on a physical channel from one DECT termination to a physical channel for another
DECT termination.
NOTE 7: The DECT termination can be a PT or an FT or another WRS.

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3.2 Abbreviations
For the purposes of this ETS, the following abbreviations apply:
AC Authentication Code
ARI Access Rights Identity
BMC Broadcast Message Control
C/O Connection Oriented mode
CK Cipher Key
CN Carrier Number
CRFP Cordless Radio Fixed Part
DCK Derived Cipher Key
DECT Digital Enhanced Cordless Telecommunications
DLC Data Link Control
ETR European Telecommunication Report
FMID Fixed part MAC Identity
FP Fixed Part
FT Fixed radio Termination
IPUI International Portable User Identity
IWU Inter Working Unit
KSG Key Stream Generator
LCE Link Control Entity
LLME Lower Layer Management Entity
MAC Medium Access Control
MBC Multi Bearer Control
MMI Man Machine Interface
NWK Network
OA&M Operation, Administration and Maintenance
PA Portable Application
PARI Primary Access Rights Identity
PARK Portable Access Rights Key
PHL Physical Layer
PMID Portable part MAC Identity
PP Portable Part
PT Portable radio Termination
PUN Portable User Number
REP Repeater Part
RFP Radio Fixed Part
RFPI Radio Fixed Part Identity
RMBC Relay Multi Bearer Control
RPN Radio fixed Part Number
RX Receive
SAP Service Access Point
SN Slot pair Number
TBC Traffic Bearer Control
TBR Technical Basis for Regulation
TPUI Temporary Portable User Identity
TX Transmit
WRS Wireless Relay station
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4 Wireless Relay Station (WRS)
4.1 Introduction
A WRS is a physical grouping that contains both Fixed radio Termination (FT) and Portable radio
Termination (PT) elements, and that transfers information between a Radio Fixed Part (RFP) and a
Portable Part (PP). The FT element acts towards a PP exactly as an ordinary RFP. The PT element acts
like a PP towards the RFP, and is locked to the closest RFP. The WRS contains inter-working between its
FT and its PT, including transparent transfer of the higher layer DECT services. WRS links may be
cascaded.
Compared to an RFP, a WRS may introduce capacity restrictions to the services offered. The restrictions
may increase with the number of cascaded WRS links (hops). Single WRS link applications can be
generally applied. However, special precautions are needed when applying cascaded WRS links. The
capacity may be too low, or there may be a need to adjust the echo control requirements.
A WRS shall comply with the general FT identities requirements for RFPs. Installing or adding a WRS to a
DECT infrastructure is not possible outside the control of the system operator/installer/owner, who
provides the required system identities, access rights and authentication/encryption keys.
4.2 Description
NWK
L
L
L
DLC
L
M
M
IWU
MAC
E
E
(FT) IWU (PT)
PHL
WRS
PT FT
Figure 1: WRS reference model, Protocol stack model

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ETS 300 700: March 1997
The WRS, as shown in figure 1, provides inter-working on the DECT air interface between a PT and an
FT as described in ETS 300 175, Parts 1 to 8, [1] - [8].
The PT may also be the PT side of a WRS in a multi-hop scenario.
The reference model of figure 1 establishes the following basic principles of the WRS:
- inter-working with PTs as defined by ETS 300 175 , Parts 1 to 8, [1] - [8];
- inter-working with FTs as defined by ETS 300 175, Parts 1 to 8, [1] - [8], with additions defined in
this ETS;
- inter-working between PT and FT side is provided at Medium Access Control (MAC) layer and
Physical (PHL) layer;
- a logical grouping of PT and WRS operates as a PT;
- a logical grouping of FT and WRS operates as a FT.
Looking towards the PT the WRS is fully protocol transparent. The PT cannot distinguish the WRS from
any other RFP within an FT. Therefore, the WRS puts no additional requirements on the PT.
4.2.1 PHL layer functions
The WRS shall fulfil the following PHL layer requirements:
- the WRS shall for the relevant packet type meet the PP requirements in ETS 300 175-2 [2] when it
is acting as a PP, and meet the RFP requirements in ETS 300 175-2 [2] when it is acting as an
RFP, except that the timing requirements in ETS 300 175-2 [2], subclause 4.2.4. shall be met by all
WRS transmissions and that the requirement in ETS 300 175-2 [2], subclause 4.2.5 on difference
between reference timers shall be disregarded;
- Z-field mapping as defined in ETS 300 175-2 [2], subclause 4.8 shall be supported.
4.2.2 MAC layer functions
The WRS provides inter-working at the MAC layer. The WRS incorporates PT and FT functions as
defined in ETS 300 175-3 [3].
The WRS shall fulfil the obligatory requirements of ETS 300 175-3 [3], subclauses 11.4 and 11.6, with the
modifications as defined in this ETS.
4.2.3 Data Link Control (DLC) layer functions
The WRS may incorporate DLC layer PT functionality to support communication with the FT according to
ETS 300 175-4 [4].
4.2.4 NWK layer functions
The WRS may incorporate NWK layer PT functionality to support communication with the FT according to
ETS 300 175-5 [5].
4.2.4.1 Over-the-air maintenance
If Operation, Administration and Maintenance (OA&M) information transfer is supported, it may use the
<> information element (see ETS 300 175-5 [5], subclause 7.7.23) in NWK layer
messages. This element can accommodate unstructured user specific data. For over the air maintenance,
a link towards the WRS is created using the PP identity of the WRS.

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4.2.5 Identities
The WRS shall have a specific Radio fixed Part Number (RPN) identity and Portable Access Rights Key
(PARK). The RPN may be transferred by over-the-air maintenance procedures. For transferring the RPN
to the WRS, the Fixed Identity information element with identity type "ARI + RPN for WRS" should be
used.
The WRS may have additional specific PT identities when PT DLC and NWK layer functionality is
included.
4.3 Services
The WRS may be used in all applications as defined in ETR 043 [9]. Typical WRS applications are
presented in ETR 246 [10].
The WRS shall provide a relay service for MAC layer connection oriented, broadcast and connectionless
services as defined in ETS 300 175-3 [3], subclauses 5.6 and 5.7.
The WRS shall provide the services as given in table 1.
Table 1: WRS services
Offered service Support Comment
S.1 Transparency between PT and FT Yes
S.2 MAC services Yes All, see ETS 300 175-3 [3]
S.3 Over the air maintenance Optional
S.4 PT services Optional As applicable for a certain application (e.g.
(e.g. authentication) based on a profile)
4.4 Procedures
4.4.1 PHL layer
The WRS shall conform to the PT and FT procedures as defined by ETS 300 175-2 [2].
4.4.2 MAC layer
The WRS shall conform to the PT and FT procedures as defined by ETS 300 175-3 [3].
4.4.2.1 Extended fixed part capabilities
The FP can control the hop configuration and indicate the admitted WRS scenarios by means of the
extended fixed part capabilities message (see ETS 300 175-3 [3]).
The extended fixed part capabilities message shall be sent by all WRSs at least once every 8 multiframes,
and all WRSs shall understand this message. The WRS shall assume all WRS support bits being set to
"0" when the FT does not transmit the message.
4.4.2.2 Hop control
The WRS that is locked to an FT shall decrease the value HOPS (when > 0) of the corresponding WRS
type (CRFP or REP respectively; see chapters 5 and 6) in the received extended fixed part capabilities
message (see ETS 300 175-3 [3], subclause 7.2.3.5.2.1) for the transmission of its own extended fixed
part capability information.
NOTE: The number of hops should be no more than one. Use of more than one hop may be
subject to agreement with national radio authorities.

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5 Cordless Radio Fixed Part (CRFP)
This clause defines requirements in addition to the general requirements for the WRS in clause 4.
5.1 Description
5.1.1 General
This description avoids defining specific implementations of the CRFP for a certain application.
ETR 246 [10] clarifies the operation of the CRFP for typical applications. This description defines the
architecture model of the CRFP and additional messages and procedures necessary to support the
CRFPs in the DECT environment.
In this description the full slot frame multiplexing structure and IN_minimum_delay speech service are
used for descriptive purposes only, and not to restrict the application of the CRFP to a specific slot
structure or service.
5.1.2 Reference model
The reference model of figure 1 is applicable for the CRFP. The PT side of the CRFP is called CRFP_PT.
The FT side of the CRFP is called CRFP_FT.
To support a CRFP, the following additional procedures are defined for the FT:
- MAC layer: access control of CRFP (for specific information transfer to CRFPs);
- NWK layer: Cipher Key (CK) transfer to CRFP.
The following functions are defined for the CRFP based on ETS 300 175, Parts 1 to 8 [1] - [8]:
- FT and PT PHL and MAC layer to provide independent bearer control to PTs and FT;
- a selection of PT DLC and NWK layer to support communication between CRFP and FT.
The following additional functions and procedures are defined for the CRFP:
- IWU at MAC and PHL layer to provide inter-working between CRFP_PT and CRFP_FT;
- access control procedures to support both relay and local handling of data on the same bearer;
- CK uploading and initialization for CRFP_FT MAC.
5.1.3 MAC layer functions
5.1.3.1 General
The basic function of the CRFP is defined by its frame multiplexing structure. Procedures are defined
based on this structure to allow the CRFP to support required services.

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5.1.3.2 Frame multiplexing structure
Figure 2 shows the typical frame multiplexing structure for a CRFP that supports full slots with
IN_minimum_delay.
TX RX TX
RFP
RX TX TX RX
RX TX TX RX
CRFP
RX TX RX
PP
Figure 2: Typical frame multiplexing structure of the CRFP
The frame multiplexing structure supports a combination of both links with PTs and FTs. In this dual frame
multiplexing structure the CRFP may transmit or receive during any slot of a frame. A duplex bearer to
either the PT or FT is still supported by a combination of an CRFP Receive (RX) and Transmit (TX) slot
separated by one half frame.
The CRFP shall support the frame multiplexing structure defined as:
- CRFP-PT frames and CRFP-FT frames are synchronized to the FT frames;
- CRFP-PT and CRFP-FT bearer control complies at least with ETS 300 175-3 [3] (e.g. Duplex
bearers are separated by one half frame);
- relayed logical channels are buffered to support MAC multiplexing rules of CRFP-PT and CRFP-FT;
- available slots of the CRFP are marked to be either Receive (RX) or Transmit (TX) slots. A slot
shall be regarded as TX slot only when it is actually used for transmission.
NOTE 1: During the first half frame (e.g. Slot 0 to 11) all RX slots listen to FT transmissions and
all TX slots transmit to PTs. During the second half frame all RX slots listen to PTs and
all TX slots shall transmit to FT.
- RX and TX slots of one relayed bearer belong to the same half frame.
NOTE 2: In idle mode the CRFP listens to an FT during all frames, transmits at least one
dummy bearer (see ETS 300 175-3 [3]) to PTs and performs receiver scanning on all
other slots. Idle receiver scanning is done in accordance with PT and FT idle receiver
scan procedures.
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ETS 300 700: March 1997
5.1.3.3 Logical channel mapping
The CRFP_PT and CRFP_FT shall fulfil the multiplexing rules as defined in ETS 300 175-3 [3].
Handling of logical channel data received at CRFP_PT shall be as follows:
ME-SAP (Q, N, P, M): data shall be delivered to the Lower Layer Management Entity (LLME) of
CRFP. The LLME of the CRFP shall also generate information for the BMC of
the CRFP_FT;
MA-SAP (B ): data shall be delivered to the higher layer and to the IWU of the CRFP. The
S
IWU shall issue a MAC-PAGE.Req for the BMC of the CRFP_FT;
MB-SAP (C , SI , SI ): data shall be delivered to the higher layer and to the IWU of the CRFP;
L N P
MC-SAP (C, I, G ): U-plane data shall always be relayed by the IWU. Depending on the CRFP
F
state, the C-plane data shall be delivered as follows:
- in "local state", all C-plane data is delivered to higher layers;
- in "relay state", all C-plane data is delivered to the IWU for relay at
CRFP_FT.
The local and relay state of a connection are defined in subclause 5.3.1.1.
All other logical channel data is handled locally in the CRFP_PT and CRFP_FT MAC. Logical channel
data received at CRFP_FT related to the MB-SAP and MC-SAP shall be delivered to the IWU for relay.
ME-SAP data shall be delivered to the LLME of the CRFP.
Delay logical channels:
Logical channel information that is relayed in the CRFP shall bear a minimum delay within the constraints
of the multiplexing rules as defined in subclause 6.2.2 of ETS 300 175-3 [3]. IN_minimum_delay
information, like speech, shall be relayed in the same or next frame, depending upon bearer position.
5.1.3.4 Quality Control and Flow Control
The CRFP has separate quality control and flow control on the two links.
For C-channel and I channel flow control, for antenna switch requests and sliding collision detection, the
P
BCK and Q2 bits shall be used for each link and the procedures as described in ETS 300 175-3 [3] shall
be followed for each link independently.
If the CRFP receives a B-field with corrupt I data (X-CRC failed) then it shall relay this data and change
N
the B-field identifications (a , a and a bits) to "001"B.
4 5 6
If the CRFP receives a B-field with corrupt I error detect data then it shall relay this data and change the
P
B-field identifications (a , a and a bits) to "000" B.
4 5 6
5.1.4 NWK layer functions
Additional functionality in NWK layer and LLME of both FT and CRFP is defined to support over-the-air CK
transfer (for encryption of relayed connections) and OA&M.

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ETS 300 700: March 1997
5.1.5 Identities
5.1.5.1 Identities and addressing
The connections in the CRFP are identified by Portable part MAC Identities (PMIDs).
Relayed connections shall use the PMID of a PT.
Connections in local state shall use a PMID of the CRFP. To allow multiple local connections
simultaneously, the CRFP shall provide multiple PMIDs. Each PMID should be related to a different
International Portable User Identity (IPUI) of the CRFP. Therefore the CRFP may comprise multiple IPUIs.
Both in relay state and local state, the FMID used to address a CRFP is derived from the PARI of the FT
and the RPN of the CRFP and the FMID used to address a RFP is derived from the PARI of the FT and
the RPN of the RFP according to ETS 300 175-3 [3].
The PARK should be the same for all IPUIs of the CRFP.
At the NWK layer the FT can address the CRFP as a PT. The CRFP may define one IPUI of the available
ones, that shall be used for over-the-air maintenance. The FT may address other IPUIs of the CRFP to
derive Derived Cipher Key (DCK) from a User Authentication Key (UAK).
5.1.5.2 Subscription data
In order to ensure inter-working of the CRFP within a FP with PTs, it is necessary to install the parameters
given in table 2 into the CRFP during subscription. The installation procedure is implementation
dependent and may require a Man Machine Interface (MMI). It is recommended to use over-the-air
maintenance procedures to allow on-air installation of most parameters.
Table 2: CRFP parameters
Parameter Optional/ Value Comment
Mandatory
RPN M All PARI is relayed from FT and combined with RPN
of CRFP to provide RFPI
PARK M All PARK should be the same for all CRFP users
IPUI (1.n) O All n is the number of CRFP users
UAK/AC (1.n) O All n is the number of CRFP users
CK O All CK may be derived from UAK
NOTE: The number of CRFP users is the maximum number of simultaneous connections
from the CRFP that require higher layer control in the CRFP.
5.2 Messages
5.2.1 MAC layer control
The CRFP uses the messages indicated with "**" in ETS 300 175-3 [3], subclauses 7.2.5.2.2, 7.2.5.3.1
and 7.3.3.1 only, with the "first PT transmission" code for the first transmission to an FT. For all other
transmissions of these messages the CRFP shall use these messages without the "first PT transmission"
code.
In all following message diagrams, the notation access.req indicates an access.req message with the "first
PT transmission" code, and the notation *access.req indicates a message without the "first PT
transmission" code.
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5.3 Procedures
5.3.1 MAC layer
5.3.1.1 Connection Oriented mode (C/O) procedures at CRFP
The following procedures provide means to address CRFPs on one physical relayed connection of a FT
with a PT. The connection with the PT is either in relay state or local state. In relay state, all higher layer
C-plane signalling shall be relayed by the CRFPs between FT and PT. In local state, all higher layer C-
plane signalling shall be buffered at the FT and CRFP. The local state is a temporary state to allow higher
layer communication between FT and a specific CRFP.
5.3.1.1.1 Creation of a Relay Multi Bearer Control (RMBC)
To perform a relay function in the CRFP, a RMBC is defined in the MAC IWU. The creation of an RMBC in
the IWU of the CRFP is very similar to the creation of MBCs as specified in ETS 300 175-3 [3],
subclause 10.2.4.1.
To set-up a relay service the RMBC can use a normal bearer set-up or a dual bearer set-up depending on
the current mode of the CRFP (subclause 5.3.5.1).
5.3.1.1.2 Normal C/O bearer set-up
Using the normal bearer set-up the FT does not recognize that the bearer set-up is arriving from a CRFP,
the CRFP_PT operates as a PT. The CRFP connection shall always be in "relay state".
Below the calling side shall be the initiating PT or FT for a bearer set-up. The called side shall be the
destination PT or FT. Figure 3 shows the time-message diagram for basic set-up.
PT CRFP FT
SN 10 SN 2
access.req
{bearer_PT.req}
wait
wait access.req (PT)
wait bearer.cfm (PT)
wait other
bearer.cfm {bearer_PT.cfm} other
other
other
{bearer_established}
Figure 3: Normal relay bearer set-up

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ETS 300 700: March 1997
During the bearer set-up procedures TBC , that has been created at the CRFP due to a
"access_request", requests the LLME to be connected to an MBC. If the connection does not exist, the
LLME shall create an RMBC in the CRFP. In the mean time TBC transmits "wait" messages to the calling
side.
The RMBC shall create a new TBC (TBC ) at the other side of the CRFP and shall issue the called
address (FMID/PMID) and physical channel description to TBC . The PMID and FMID of the called and
calling parties shall be used (not a CRFP PMID, FMID). The CRFP TBC initiates a bearer set-up by
transmitting the corresponding "access_request" to the called side.
If the bearer set-up is successful (after "other" received error free) TBC reports "bearer_established" to
the RMBC. The RMBC informs the LLME that the requested MBC is connected and TBC is allowed to
transmit "bearer_confirm" to the calling side.
5.3.1.1.3 Dual C/O bearer set-up
Using the dual bearer set-up the FT shall recognize that the bearer set-up is arriving from a CRFP. The
FT can therefore control the state of the CRFP connection using the connection identity of CRFP local
service (specific PMID).
Below the calling side is the initiating PT or FT for a bearer set-up. The called side is the destination PT or
FT. Additional access procedures for the FT are defined below. Figure 4 shows the time-message
diagram for basic connections.
PT CRFP FT
SN 2
SN 10
access.req
{bearer_PT.req}
wait
{local state}
access.req (CP)
bearer.cfm (CP)
...........
other
{bearer_CP.cfm}
other
wait *access.req (PT)
bearer.cfm {bearer_PT.cfm} bearer.cfm (PT)
{relay state}
other
other
{bearer_established}
Figure 4: Dual relay bearer set-up

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ETS 300 700: March 1997
At the CRFP
During the bearer set-up procedures the TBC, that has been created at the CRFP due to a
"access_request", asks the LLME to be connected to an MBC. If the RMBC related to this connection
does not exist, the LLME creates an RMBC and a MBC for the CRFP_PT and CRFP is by definition in
"local state". In "local state" the RMBC activities are suspended. The creation of the MBC is reported to
the DLC by issuing a MAC-CON.Ind primitive after the first successful bearer set-up with the FT.
The MBC creates a TBC for set-up of a single duplex bearer connection (with the same slot type as
requested by the PT) to an FT and issues the called address (FMID/PMID) and physical channel
description to the new TBC. The PMID of the CRFP shall be used.
NOTE: This connection is necessary for CK transfer.
After the TBC has reported "bearer_established" to the MBC, the MBC reports the successful set-up of
the connection to the LLME, which changes the state of the CRFP for this connection to "relay state". The
MBC activities are now suspended and RMBC activities are resumed.
If a TBC exists with the called side, the RMBC shall now relay the "access_request" on that TBC without
the "first PT transmission" code, with the PMID and FMID of the called and calling parties (not a CRFP
PMID, FMID).
If the bearer set-up is successful (after "other" received error free) the TBC reports "bearer_established"
to the RMBC. The RMBC informs the LLME that the requested MBC at the called side is connected and
the TBC is allowed to transmit "bearer_confirm" to the calling side.
5.3.1.1.4 C/O connection release
At the CRFP
When the CRFP receives a release message with the PMID indicating the MBC of the CRFP, the CRFP
shall release that MBC.
When the CRFP RMBC is released, the CRFP shall release all corresponding TBCs and MBC at both
CRFP_PT and CRFP_FT.
Figure 5 shows the procedure for basic connections.

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ETS 300 700: March 1997
PT CRFP FT
SN 2
release (PT)
SN 10
release (PT)
release (PT)
release (PT)
Figure 5: Release
5.3.1.1.5 C/O abnormal connection release
If the CRFP detects an abnormal
...