SIST EN 300 175-4 V2.1.1:2008

• Abstract:

  The present document is one of the parts of the specification of the Digital Enhanced Cordless Telecommunications (DECT) Common Interface (CI). The present document specifies the Data Link Control (DLC) layer. The DLC layer is part 4 of the DECT CI standard and layer 2b of the DECT protocol stack. Two planes of operation are specified for this DLC (sub)layer. These planes are called the Control plane (C-plane) and the User plane (U-plane). The C-plane is mostly concerned with the DECT signalling aspects. It provides a reliable point-to-point service that uses a link access protocol to offer error protected transmission of Network (NWK) layer messages. The C-plane also provides a separate point-to-multipoint (broadcast) service (Lb). The U-plane is only concerned with end-to-end user information. This plane contains most of the application dependent procedures of DECT. Several alternative services (both circuit-mode and packet-mode) are defined as a family of independent entities. Each service provides one or more point-to-point U-plane data links, where the detailed characteristics of those links are determined by the particular needs of each service. The defined services cover a wide range of performance, from "unprotected with low delay" for speech applications to "highly protected with variable; delay", for local area network applications. NOTE: The performance of the DLC services need not be tight to any particular application. For example the "unprotected with low delay" service could also be used for data applications, e.g. if some data protection is provided outside the DECT protocol. The present document uses the layered model principles and terminology as described in ITU-T Recommendation X.200 [12] and ITU-T Recommendation X.210 [13]. The present document includes New Generation DECT, a further development of the DECT standard introducing wideband speech, improved data services, new slot types and other technical enhancements.

• Status: Published
• Publication Date: 27-Jan-2008
• ICS: 33.070.30 - Digital Enhanced Cordless Telecommunications (DECT)
• ICS: 35.100.20 - Data link layer
• Technical Committee: MOC - Mobile Communications
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 17-Jan-2008
• Due Date: 23-Mar-2008
• Completion Date: 28-Jan-2008
• Ref Project: ETSI EN 300 175-4 V2.1.1 (2007-08) - Digital Enhanced Cordless Telecommunications (DECT); Common Interface (CI); Part 4: Data Link Control (DLC) layer

SIST EN 300 175-4 V2.1.1:2008 is the Slovenian version of ETSI EN 300 175-4 V2.1.1 for Digital Enhanced Cordless Telecommunications (DECT) Common Interface. It specifies the Data Link Control (DLC) layer, which is layer 2b of the DECT protocol stack, and defines how DECT signalling and user data are carried between the MAC layer and the Network (NWK) layer. It is written for implementers of DECT cordless systems, including terminal, base station and interworking equipment.

What does SIST EN 300 175-4 V2.1.1:2008 specify?

SIST EN 300 175-4 V2.1.1:2008 specifies the DECT DLC layer as part 4 of the Common Interface. It covers both control traffic and user traffic, including the New Generation DECT additions mentioned in the scope.

The document is organized into clauses for scope, references, definitions, the DLC overview, C-plane service characteristics, C-plane frame structures, peer-to-peer procedures, primitives, management procedures, U-plane service characteristics and U-plane frame structures.

In practice, that means the standard tells implementers how to build the DLC functions that sit between MAC and NWK, how to format the bits in frames, and how to move data reliably or unacknowledged depending on the service.

What are the key requirements of SIST EN 300 175-4 V2.1.1:2008?

C-plane service, addressing and frame handling

SIST EN 300 175-4 V2.1.1:2008 defines a reliable point-to-point C-plane service for Network (NWK) messages and a separate broadcast service called Lb. That matters because signalling traffic is handled differently from user payload and needs clear routing rules.

• Clause 5 defines the C-plane link access protocol service and the broadcast service.
• Clause 6 defines the C-plane frame structures, including general frame structure and broadcast frame structure.
• Clause 7 defines the address and control fields, including RES, C/R, SAPI, NLF, LLN, DLI and the I, S and U control formats.
• Invalid frames are discarded without notification to the sender, so implementations must rely on the protocol state rather than recovery from error reports.
• The C-plane commands and responses include I, RR, RNR, REJ, SABM, DM, UI, DISC and UA, which means the link can acknowledge data, report busy conditions, recover from exceptions and terminate or re-establish operation.

Primitives and management

SIST EN 300 175-4 V2.1.1:2008 defines abstract layer primitives for service interaction between DLC, NWK and the interworking unit. In practice, these are the service access points implementers use to connect the protocol logic to the rest of the stack.

• Clause 8 defines primitive types req, cfm, ind and res.
• The NWK-facing primitives include DL_ESTABLISH, DL_RELEASE, DL_DATA, DL_UNIT_DATA, DL_SUSPEND, DL_RESUME, DL_ENC_KEY, DL_ENCRYPT, DL_SERVICE_MOD, DL_BROADCAST and DL_EXPEDITED.
• The interworking-unit primitives include DL_U_DATA, DL_U_UNIT_DATA and DL_U_ERROR.
• Clause 10 covers LLME, MAC connection management, LAPC management, LUX management, connection handover, ciphering management and broadband data link management.
• The DLI and DLEI definitions tie DLC entities to MAC connection identifiers, which is important for routing and for identifying the right link endpoint.

U-plane services

SIST EN 300 175-4 V2.1.1:2008 defines a family of U-plane services for end-to-end user information. These services range from transparent and unprotected transport to protected, segmented and rate-adapted data paths.

• Clause 11 defines LU1 TRansparent UnProtected service (TRUP), LU2 Frame RELay service (FREL), LU3 Frame SWItching service (FSWI), LU4 Forward Error Correction (FEC) service and LU5 Basic Rate Adaption service (BRAT).
• The same clause also defines LU7 64 kbit/s data bearer service, LU9 Unprotected Rate Adaption for V series Equipment (RAVE), LU10 Enhanced Frame RELay (EFREL) service and LU11 64 kbit/s bearer service.
• These services use different transmission classes, buffering, segmentation, retransmission and error-control methods, so the selected LUx service must match the kind of user data being carried.
• Clause 12 defines the U-plane frame structures FU1 to FU10, which is what implementers use to map SDUs into actual air-interface frames.

What terms does SIST EN 300 175-4 V2.1.1:2008 define?

• C-plane - The control plane for DECT signalling, used for reliable point-to-point and broadcast control traffic.
• U-plane - The user plane for end-to-end user information and application-dependent procedures.
• LAPC - The DLC layer C-plane protocol entity that handles C-plane link operation.
• LLME - The Lower Layer Management Entity that manages lower-layer functions such as connections and ciphering.
• LLN - The Logical Link Number used to identify a DLC link instance.
• DLI - The Data Link Identifier formed from LLN and MCI to identify a LAPC instance.
• BRAT - The Basic Rate AdapTion service used for LU5 rate adaptation and multiplexing.
• RAVE - The Unprotected Rate Adaption for V series Equipment service defined as LU9.

Who uses SIST EN 300 175-4 V2.1.1:2008?

SIST EN 300 175-4 V2.1.1:2008 is used by DECT device designers, protocol stack developers and chipset or firmware teams that implement the DLC layer. It is also used by engineers working on Fixed radio Termination (FT) and Portable radio Termination (PT) equipment, especially where signalling, broadcast, handover or ciphering must be supported.

Quality and test teams use it to verify frame formats, primitive behavior, link recovery, sequencing and service selection. Interworking and terminal-adaptation designers use it for LU services such as LU7, LU9, LU10 and LU11.

Which standards are used with SIST EN 300 175-4 V2.1.1:2008?

• ETSI EN 300 175-1 - Provides the overall DECT Common Interface overview and the base definitions used across the series.
• ETSI EN 300 175-2 - Defines the DECT Physical Layer (PHL), which carries the frames used by the DLC layer.
• ETSI EN 300 175-3 - Defines the DECT Medium Access Control (MAC) layer and the primitives below DLC.
• ETSI EN 300 175-5 - Defines the Network (NWK) layer and the mapping of higher-layer messages used by several DLC services.
• ETSI EN 300 175-6 - Defines identities and addressing used in DECT procedures.
• ETSI EN 300 175-8 - Covers speech coding and transmission.
• ETSI TS 144 006 - Provides a related data link layer specification referenced for interoperability context.
• ITU-T Q.920 and Q.921 - Provide data link layer concepts and procedures used as the basis for some DLC field and command behavior.
• ITU-T V.42 and ITU-T V.110 - Support error-correction and data terminal adaptation concepts used by some U-plane services.
• ITU-T X.200 and ITU-T X.210 - Provide the OSI layering terminology used in the document.
• ISO/IEC 8073 - Provides the checksum basis referenced for the underlying checksum calculation.

What does the SIST EN 300 175-4 V2.1.1:2008 document contain?

The document contains bit-field definitions, frame layouts, command and response codings, and procedures for acknowledged, unacknowledged and broadcast communication. It also includes management rules for connection setup, release, modification, handover and ciphering.

Clause 7 gives the detailed coding of C-plane address and control fields, including sequence-number handling and the checksum basis. Clause 9 gives the operating procedures for class A, class B and class U links, broadcast handling and MAC-layer interfaces. Clause 11 gives the service-specific buffering, segmentation, retransmission, FEC and rate-adaptation procedures for the LU services. Clause 12 defines the U-plane frame structures that the services use when data is actually put on the air interface.

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Digital Enhanced Cordless Telecommunications (DECT) - Common Interface (CI) - Part 4: Data Link Control (DLC) layer35.100.20Podatkovni povezovalni slojData link layer33.070.30'(&7Digital Enhanced Cordless Telecommunications (DECT)ICS:Ta slovenski standard je istoveten z:EN 300 175-4 Version 2.1.1SIST EN 300 175-4 V2.1.1:2008en01-marec-2008SIST EN 300 175-4 V2.1.1:2008SLOVENSKI
STANDARD
ETSI ETSI EN 300 175-4 V2.1.1 (2007-08) 2
Reference REN/DECT-000241-4 Keywords DECT, IMT-2000, mobility, radio, TDD, TDMA ETSI 650 Route des Lucioles F-06921 Sophia Antipolis Cedex - FRANCE
Tel.: [phone]
Fax: [phone]
Siret N° 348 623 562 00017 - NAF 742 C Association à but non lucratif enregistrée à la Sous-Préfecture de Grasse (06) N° 7803/88
Important notice Individual copies of the present document can be downloaded from: http://www.etsi.org The present document may be made available in more than one electronic version or in print. In any case of existing or perceived difference in contents between such versions, the reference version is the Portable Document Format (PDF). In case of dispute, the reference shall be the printing on ETSI printers of the PDF version kept on a specific network drive within ETSI Secretariat. Users of the present document should be aware that the document may be subject to revision or change of status. Information on the current status of this and other ETSI documents is available at http://portal.etsi.org/tb/status/status.asp If you find errors in the present document, please send your comment to one of the following services: http://portal.etsi.org/chaircor/ETSI_support.asp 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 2007. All rights reserved.
DECTTM, PLUGTESTSTM and UMTSTM are Trade Marks of ETSI registered for the benefit of its Members. TIPHONTM and the TIPHON logo are Trade Marks currently being registered by ETSI for the benefit of its Members. 3GPPTM is a Trade Mark of ETSI registered for the benefit of its Members and of the 3GPP Organizational Partners. SIST EN 300 175-4 V2.1.1:2008

ETSI ETSI EN 300 175-4 V2.1.1 (2007-08) 3
Contents Intellectual Property Rights.11 Foreword.11 1 Scope.12 2 References.13 3 Definitions, symbols and abbreviations.14 3.1 Definitions.14 3.2 Symbols.14 3.3 Abbreviations.14 4 Data Link Control (DLC) layer overview.16 4.1 General.16 4.2 C-plane services.16 4.3 U-plane services.17 4.4 Lower Layer Management Entity (LLME).20 5 C-plane service characteristics.20 5.1 Data link service (LAPC+Lc).20 5.1.1 General.20 5.1.2 LAPC types of operation.21 5.1.3 Establishment of information transfer modes.21 5.1.3.1 Data Link Identifier (DLI).21 5.1.3.2 LAPC states.21 5.2 Broadcast service (Lb).22 6 Frame structures for C-plane services.23 6.1 Data link service frame structure.23 6.1.1 General frame structure.23 6.1.2 Lc frame delimiting and transparency.24 6.1.3 Transmission order.24 6.1.4 Routing to logical channels.24 6.1.4.1 CF/CLF logical channel.24 6.1.4.2 CS/CLS logical channel.25 6.1.5 Invalid frames.25 6.2 Broadcast service frame structure.26 6.2.1 Standard frame structure.26 6.2.2 Extended frame structure.26 7 Elements of procedures and formats of fields for C-plane peer-to-peer communication.27 7.1 General.27 7.2 Address field formats.27 7.3 Address field parameters.27 7.3.1 REServed bit (RES).27 7.3.2 Command Response (C/R) bit.27 7.3.3 SAPI field.27 7.3.4 New Link Flag (NLF) bit.28 7.3.5 LLN-field.28 7.3.6 Data Link Identifiers (DLI).28 7.4 Control field formats.28 7.5 Control field parameters.29 7.5.1 Poll/Final (P/F) bit.29 7.5.2 Multiple frame operation variables and sequence numbers.29 7.5.2.1 Modulus.29 7.5.2.2 Send state Variable V(S).29 7.5.2.3 Acknowledge state Variable V(A).30 7.5.2.4 Send sequence Number N(S).30 7.5.2.5 Receive state Variable V(R).30 SIST EN 300 175-4 V2.1.1:2008

ETSI ETSI EN 300 175-4 V2.1.1 (2007-08) 4
7.5.2.6 Receive sequence Number N(R).30 7.5.3 Unacknowledged operation variables and sequence numbers.30 7.5.4 Supervisory and Unnumbered function bits S and U.30 7.6 Length indicator field format.30 7.7 Length indicator field parameters.31 7.7.1 Length indicator field extension bit (N).31 7.7.2 More data bit (M).31 7.7.3 Length parameter (LI).31 7.7.4 Extended length parameter (LJJ).32 7.7.5 Reserved bit (RES).32 7.8 Fill field format.32 7.9 Checksum field format.32 7.10 Checksum field parameters.32 7.11 Commands and responses.33 7.11.1 Information (I) command.34 7.11.2 Receive Ready (RR) command/response.34 7.11.3 Receive Not Ready (RNR) command/response.35 7.11.4 REJect (REJ) command/response.35 7.11.5 Set Asynchronous Balanced Mode (SABM) command.35 7.11.6 Disconnect Mode (DM) response.35 7.11.7 Unnumbered Information (UI) command.35 7.11.8 DISConnect (DISC) command.36 7.11.9 Unnumbered ACK (UA) response.36 8 Primitives.36 8.1 Primitive types.36 8.2 Primitives to the MAC layer (lower layer).36 8.3 Primitives to the NWK layer (higher layer).36 8.3.1 Parameter definitions.37 8.3.2 S-SAP primitives.38 8.3.2.1 DL_ESTABLISH primitive.38 8.3.2.2 DL_RELEASE primitive.38 8.3.2.3 DL_DATA primitive.39 8.3.2.4 DL_UNIT_DATA primitive.39 8.3.2.5 DL_SUSPEND primitive.39 8.3.2.6 DL_RESUME primitive.39 8.3.2.7 DL_ENC_KEY primitive.40 8.3.2.8 DL_ENCRYPT primitive.40 8.3.2.9 DL_SERVICE_MOD primitive.40 8.3.3 B-SAP primitives.40 8.3.3.1 DL_BROADCAST primitive.41 8.3.3.2 DL_EXPEDITED primitive.41 8.4 Primitives to the interworking unit.41 8.4.1 Parameter definitions.41 8.4.2 LUX-SAP primitives.42 8.4.2.1 DL_U_DATA primitive.42 8.4.2.2 DL_U_UNIT_DATA primitive.42 8.4.2.3 DL_U_ERROR primitive.42 9 C-plane peer-to-peer procedures.43 9.1 General.43 9.2 Point to point acknowledged operation.43 9.2.1 Procedure for the use of the P/F bit.43 9.2.1.1 Class A acknowledged information transfer.43 9.2.1.2 Class B acknowledged information transfer.44 9.2.2 Use of LLN.44 9.2.2.1 Class A operation.44 9.2.2.2 Class B operation.44 9.2.3 Link establishment and information transfer in class A operation.44 9.2.3.1 Establishing class A operation.44 9.2.3.2 Class A acknowledged information transfer.45 9.2.3.3 Transmission of class A I-frames.45 SIST EN 300 175-4 V2.1.1:2008

ETSI ETSI EN 300 175-4 V2.1.1 (2007-08) 5
9.2.3.4 Reception of class A I-frames.46 9.2.3.5 Receiving acknowledgements.46 9.2.3.6 Waiting for acknowledgement.46 9.2.3.7 Release of class A operation.47 9.2.3.8 Re-establishment of class A operation.47 9.2.4 Establishing class B multiple frame operation.47 9.2.4.1 Overview.47 9.2.4.2 Class B multiple frame establishment procedures.48 9.2.4.3 Class B LLN assignment procedures.49 9.2.4.3.1 PT establishment.49 9.2.4.3.2 FT establishment.50 9.2.5 Link maintenance and information transfer in class B multiple frame operation.50 9.2.5.1 Transmitting I-frames.50 9.2.5.2 Receiving I-frames.51 9.2.5.2.1 P bit set to 1.51 9.2.5.2.2 P bit set to 0.51 9.2.5.3 Sending and receiving acknowledgements.51 9.2.5.3.1 Sending acknowledgements.51 9.2.5.3.2 Receiving acknowledgements.51 9.2.5.4 Receiving REJ-frames.52 9.2.5.5 Receiving RNR-frames.53 9.2.5.6 LAPC own receiver busy condition.54 9.2.5.7 Waiting acknowledgement.54 9.2.5.8 Appropriate supervisory frame.55 9.2.6 Release of class B multiple frame operation.55 9.2.7 Link suspension and resumption.56 9.2.7.1 Link suspension.56 9.2.7.1.1 Class B acknowledged suspend.56 9.2.7.1.2 Unacknowledged suspend.57 9.2.7.2 Class B link resumption.58 9.2.7.3 Connection handover.59 9.2.7.3.1 Class A connection handover.60 9.2.7.3.2 Class B connection handover.61 9.2.7.3.3 Expiry of connection handover timer.61 9.2.8 Re-establishment of class B multi-frame operation.61 9.2.8.1 Criteria for re-establishment.61 9.2.8.2 Procedure.62 9.2.9 Exception handling.62 9.2.9.1 General.62 9.2.9.2 Class B exception condition reporting and recovery.63 9.2.9.2.1 N(S) sequence error.63 9.2.9.2.2 N(R) sequence error.63 9.2.9.2.3 Timer recovery condition.63 9.2.9.2.4 Collision of identical transmitted and received commands.63 9.3 Unacknowledged operation.64 9.3.1 Use of LLN for unacknowledged information transfer.64 9.3.2 Class U link establishment.64 9.3.3 Unacknowledged information transfer.64 9.3.3.1 Transmission of unacknowledged information.64 9.3.3.2 Reception of unacknowledged information.64 9.3.4 Unacknowledged release.64 9.4 Broadcast operation.65 9.4.1 Normal operation.65 9.4.1.1 Procedure in the Fixed radio Termination (FT).65 9.4.1.2 Procedure in the Portable radio Termination (PT).65 9.4.2 Expedited operation.65 9.4.2.1 Procedure in the Fixed radio Termination (FT).65 9.4.2.2 Procedure in the Portable radio Termination (PT).65 9.5 MAC layer interfaces.66 9.5.1 MC-SAP.66 9.5.1.1 C-plane overview.66 9.5.1.2 C-plane service data procedures.66 SIST EN 300 175-4 V2.1.1:2008

ETSI ETSI EN 300 175-4 V2.1.1 (2007-08) 6
9.5.1.3 U-plane service data.67 9.5.2 MB-SAP.67 9.5.2.1 C-plane service data procedures.67 9.5.2.2 U-plane service data.67 9.5.3 MA-SAP.68 9.5.3.1 Overview.68 9.5.3.2 Service data procedures.68 10 Management procedures.68 10.1 Lower Layer Management Entity (LLME).68 10.2 MAC connection management.69 10.2.1 MAC connection set-up.69 10.2.2 MAC connection release.69 10.2.3 MAC connection modification.69 10.2.4 MAC connection identifiers.70 10.2.4.1 Overview.70 10.2.4.2 Advanced MAC Connection Identifiers (AMCI).70 10.2.4.3 Basic MAC Connection Identifiers (BMCI).71 10.2.4.4 MAC Connection Endpoint Identifier (MCEI).71 10.2.5 Selection of logical channel (CS or CF).71 10.3 DLC C-plane (LAPC) management.72 10.3.1 Provision of link signature.72 10.3.2 Routing of connection oriented links.72 10.3.3 Routing of connectionless links.73 10.4 DLC U-plane (LUX) management.73 10.4.1 U-plane establishment.73 10.4.2 U-plane release.73 10.4.3 U-plane suspend and resume.73 10.5 Connection handover management.74 10.6 Ciphering management.74 10.6.1 Ciphering management in cases where the NWK layer executes the ciphering related MM procedure.74 10.6.1.1 Providing a key to the MAC layer.74 10.6.1.2 Starting and stopping the ciphering.75 10.6.1.3 Connection handover.75 10.6.2 Ciphering management in cases where the NWK layer does not execute the ciphering related MM procedure.75 10.7 Broadband data link management.75 11 U-plane service characteristics.76 11.1 General.76 11.2 LU1 TRansparent UnProtected service (TRUP).76 11.3 LU2 Frame RELay service (FREL).77 11.3.1 General.77 11.3.2 Checksum operation.78 11.3.3 Segmentation and transmission class.78 11.3.4 Data transmission.79 11.3.4.1 Send side procedure.79 11.3.4.2 Receive side procedure.79 11.4 LU3 Frame SWItching service (FSWI).80 11.5 LU4 Forward Error Correction (FEC) service.80 11.6 LU5 Basic Rate Adaption service (BRAT).81 11.6.1 Overview.81 11.6.2 Protected service operation.82 11.6.2.1 General.82 11.6.2.2 Data buffering and initial rate adaptation.82 11.6.2.3 Multi-channel set multiplexing.83 11.6.2.4 Segmentation of Multiplexed Data Units (MDU).84 11.6.2.5 Frame sequencing and addition of control and fill octets.85 11.6.2.6 Frame transmission.86 11.6.3 Unprotected service operation.87 11.6.3.1 General.87 11.6.3.2 Data buffering and initial rate adaption.87 SIST EN 300 175-4 V2.1.1:2008

ETSI ETSI EN 300 175-4 V2.1.1 (2007-08) 7
11.6.3.3 Multi-channel set multiplexing.87 11.6.3.4 Segmentation of MDUs.89 11.6.3.5 Frame transmission.89 11.7 LU6 Secondary Rate AdapTion (SRAT) service.89 11.7.1 General.89 11.8 LU16 ESCape Service (ESC).90 11.8.1 General.90 11.9 LU7 64 kbit/s data bearer service.91 11.9.1 General.91 11.9.2 Physical layer service.91 11.9.3 MAC layer service.91 11.9.4 DLC layer service.91 11.9.4.1 Architectural model.91 11.9.4.1.1 Transmit (Tx) frame buffering.92 11.9.4.1.2 Receive (Rx) frame buffering.92 11.9.4.2 Automatic-Repeat-Request (ARQ) and Forward Error Control (FEC).92 11.9.4.2.1 Control field.93 11.9.4.2.2 Information field.95 11.9.4.2.3 ARQ checksum.96 11.9.4.3 Procedures for normal operation.96 11.9.4.3.1 Establishment and synchronization procedures.96 11.9.4.3.2 Active phase.98 11.9.4.3.3 Release.100 11.9.4.4 Exceptional procedures.100 11.9.4.4.1 Invalid frame condition.100 11.9.4.4.2 Establishment.100 11.9.4.4.3 Transmitting frames.100 11.9.4.4.4 Receiving frames.100 11.9.4.4.5 Sending acknowledgements.101 11.9.4.4.6 Forwarding of received data.101 11.9.4.4.7 N(R) sequence error.101 11.9.4.4.8 N(O) sequence error.101 11.9.4.4.9 N(S) sequence error.102 11.9.4.4.10 Format error.102 11.9.4.4.11 Abnormal release.102 11.9.4.4.12 Implicit reset.102 11.9.5 Network layer service.102 11.9.5.1 LCE service.102 11.9.5.2 CC service.102 11.10 LU8 service.103 11.10.1 Physical layer service.103 11.10.2
...