SIST EN 300 175-4 V1.9.1:2006

• Abstract:

  The present document gives an introduction and overview of the complete 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].

• Status: Published
• Publication Date: 28-Feb-2006
• ICS: 33.070.30 - Digital Enhanced Cordless Telecommunications (DECT)
• ICS: 35.100.20 - Data link layer
• Technical Committee: SS EIT - Technical Board for the electrotechnical, information technology and telecommunications fields
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 01-Mar-2006
• Due Date: 01-Mar-2006
• Completion Date: 01-Mar-2006
• Ref Project: ETSI EN 300 175-4 V1.9.1 (2005-09) - Digital Enhanced Cordless Telecommunications (DECT); Common Interface (CI); Part 4: Data Link Control (DLC) layer

Overview

SIST EN 300 175-4 V1.9.1:2006 sets out specifications for the Data Link Control (DLC) layer within the Digital Enhanced Cordless Telecommunications (DECT) Common Interface (CI). Developed under the direction of SIST and based on the corresponding ETSI standard, this document details layer 2b of the DECT protocol stack, focusing on reliable and efficient data exchange mechanisms essential for digital cordless telecommunication systems.

The standard outlines two main planes of operation for the DLC sublayer:

• Control plane (C-plane): Handles signaling, providing reliable, error-protected transmission of network layer messages and supporting both point-to-point and broadcast communication.
• User plane (U-plane): Focuses on the end-to-end transfer of user information, defining various services to ensure flexible support for DECT applications, including both circuit-mode and packet-mode data transfer.

By adhering to the principles and terminology of ITU-T Recommendations X.200 and X.210, this standard ensures compatibility within layered telecommunication architectures.

Key Topics

1. DLC Layer Structure and Functionality

• Defines the role of DLC as the intermediary between the Medium Access Control (MAC) layer and the Network Layer (NWK).
• Ensures data integrity through error detection and correction mechanisms.
• Manages logical data links for both signaling and user information.

2. C-plane and U-plane Services

• C-plane: Provides point-to-point and point-to-multipoint links for DECT signaling, ensuring robust error protection for management and control messages.
• U-plane: Supports both protected and unprotected data transmissions to accommodate a broad range of applications, from real-time voice exchange to data-intensive local area network (LAN) connectivity.

3. Alternative Service Modes

• Services scaled from “unprotected with low delay” (optimized for voice) to “highly protected with variable delay” (for data-centric applications).
• Offers circuit-mode and packet-mode alternatives for flexible data link management.

4. Interlayer Communication

• Specifies service access points (SAPs) and primitives for standardized communication between DLC and adjacent protocol layers.

5. Management and Security

• Includes procedures for connection establishment, maintenance, and release.
• Details lower-layer management entities, ciphering management, and support for secure, error-protected communications.

Applications

The DLC layer specified in this standard is fundamental for:

• Cordless voice services: Providing reliable, low-latency transmission for telephony applications in residential and enterprise scenarios.
• Data transfer over DECT: Enabling wireless LAN extensions, access to networked devices, and broadband data applications.
• Broadcast communications: Efficiently distributing control signals over multiple DECT devices.
• Flexible application support: Allowing diverse QoS configurations for both real-time and high-integrity data exchange.

By standardizing the DLC layer, SIST EN 300 175-4 ensures seamless interoperability among DECT equipment from different vendors and lays a foundation for scalable, secure digital telecommunication networks.

Related Standards

For comprehensive DECT system implementation, consider the following related standards:

• SIST EN 300 175-1: General overview and common interface architecture.
• SIST EN 300 175-2: Physical (PHY) layer specifications.
• SIST EN 300 175-3: Medium Access Control (MAC) layer requirements.
• SIST EN 300 175-5: Network Layer (NWK) definitions and procedures.
• ITU-T X.200 & X.210: Principles and terminology for OSI-based layered communication architectures.

These standards, together with SIST EN 300 175-4, provide a robust framework for designing and deploying digital enhanced cordless telecommunications solutions that require flexibility, reliability, and interoperability in both consumer and professional environments.

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 1.9.1SIST EN 300 175-4 V1.9.1:2006en01-marec-2006SIST EN 300 175-4 V1.9.1:2006SLOVENSKI
STANDARD
ETSI ETSI EN 300 175-4 V1.9.1 (2005-09) 2
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ETSI ETSI EN 300 175-4 V1.9.1 (2005-09) 3
Contents Intellectual Property Rights.11 Foreword.11 1 Scope.12 2 References.12 3 Definitions, symbols and abbreviations.13 3.1 Definitions.13 3.2 Symbols.13 3.3 Abbreviations.14 4 Data Link Control (DLC) layer overview.15 4.1 General.15 4.2 C-plane services.16 4.3 U-plane services.17 4.4 Lower Layer Management Entity (LLME).19 5 C-plane service characteristics.19 5.1 Data link service (LAPC+Lc).19 5.1.1 General.19 5.1.2 LAPC types of operation.20 5.1.3 Establishment of information transfer modes.20 5.1.3.1 Data Link Identifier (DLI).20 5.1.3.2 LAPC states.20 5.2 Broadcast service (Lb).21 6 Frame structures for C-plane services.22 6.1 Data link service frame structure.22 6.1.1 General frame structure.22 6.1.2 Lc frame delimiting and transparency.23 6.1.3 Transmission order.23 6.1.4 Routing to logical channels.23 6.1.4.1 CF/CLF logical channel.23 6.1.4.2 CS/CLS logical channel.24 6.1.5 Invalid frames.24 6.2 Broadcast service frame structure.25 6.2.1 Standard frame structure.25 6.2.2 Extended frame structure.25 7 Elements of procedures and formats of fields for C-plane peer-to-peer communication.26 7.1 General.26 7.2 Address field formats.26 7.3 Address field parameters.26 7.3.1 REServed bit (RES).26 7.3.2 Command Response (C/R) bit.26 7.3.3 SAPI field.26 7.3.4 New Link Flag (NLF) bit.27 7.3.5 LLN-field.27 7.3.6 Data Link Identifiers (DLI).27 7.4 Control field formats.27 7.5 Control field parameters.28 7.5.1 Poll/Final (P/F) bit.28 7.5.2 Multiple frame operation variables and sequence numbers.28 7.5.2.1 Modulus.28 7.5.2.2 Send state Variable V(S).28 7.5.2.3 Acknowledge state Variable V(A).29 7.5.2.4 Send sequence Number N(S).29 7.5.2.5 Receive state Variable V(R).29 SIST EN 300 175-4 V1.9.1:2006

ETSI ETSI EN 300 175-4 V1.9.1 (2005-09) 4
7.5.2.6 Receive sequence Number N(R).29 7.5.3 Unacknowledged operation variables and sequence numbers.29 7.5.4 Supervisory and Unnumbered function bits S and U.29 7.6 Length indicator field format.29 7.7 Length indicator field parameters.30 7.7.1 Length indicator field extension bit (N).30 7.7.2 More data bit (M).30 7.7.3 Length parameter (LI).30 7.7.4 Extended length parameter (LJJ).31 7.7.5 Reserved bit (RES).31 7.8 Fill field format.31 7.9 Checksum field format.31 7.10 Checksum field parameters.31 7.11 Commands and responses.32 7.11.1 Information (I) command.33 7.11.2 Receive Ready (RR) command/response.33 7.11.3 Receive Not Ready (RNR) command/response.34 7.11.4 REJect (REJ) command/response.34 7.11.5 Set Asynchronous Balanced Mode (SABM) command.34 7.11.6 Disconnect Mode (DM) response.34 7.11.7 Unnumbered Information (UI) command.34 7.11.8 DISConnect (DISC) command.35 7.11.9 Unnumbered ACK (UA) response.35 8 Primitives.35 8.1 Primitive types.35 8.2 Primitives to the MAC layer (lower layer).35 8.3 Primitives to the NWK layer (higher layer).35 8.3.1 Parameter definitions.36 8.3.2 S-SAP primitives.37 8.3.2.1 DL_ESTABLISH primitive.37 8.3.2.2 DL_RELEASE primitive.37 8.3.2.3 DL_DATA primitive.38 8.3.2.4 DL_UNIT_DATA primitive.38 8.3.2.5 DL_SUSPEND primitive.38 8.3.2.6 DL_RESUME primitive.38 8.3.2.7 DL_ENC_KEY primitive.39 8.3.2.8 DL_ENCRYPT primitive.39 8.3.2.9 DL_SERVICE_MOD primitive.39 8.3.3 B-SAP primitives.39 8.3.3.1 DL_BROADCAST primitive.40 8.3.3.2 DL_EXPEDITED primitive.40 8.4 Primitives to the interworking unit.40 8.4.1 Parameter definitions.40 8.4.2 LUX-SAP primitives.41 8.4.2.1 DL_U_DATA primitive.41 8.4.2.2 DL_U_UNIT_DATA primitive.41 8.4.2.3 DL_U_ERROR primitive.41 9 C-plane peer-to-peer procedures.42 9.1 General.42 9.2 Point to point acknowledged operation.42 9.2.1 Procedure for the use of the P/F bit.42 9.2.1.1 Class A acknowledged information transfer.42 9.2.1.2 Class B acknowledged information transfer.43 9.2.2 Use of LLN.43 9.2.2.1 Class A operation.43 9.2.2.2 Class B operation.43 9.2.3 Link establishment and information transfer in class A operation.43 9.2.3.1 Establishing class A operation.43 9.2.3.2 Class A acknowledged information transfer.44 9.2.3.3 Transmission of class A I-frames.44 SIST EN 300 175-4 V1.9.1:2006

ETSI ETSI EN 300 175-4 V1.9.1 (2005-09) 5
9.2.3.4 Reception of class A I-frames.45 9.2.3.5 Receiving acknowledgements.45 9.2.3.6 Waiting for acknowledgement.45 9.2.3.7 Release of class A operation.46 9.2.3.8 Re-establishment of class A operation.46 9.2.4 Establishing class B multiple frame operation.46 9.2.4.1 Overview.46 9.2.4.2 Class B multiple frame establishment procedures.47 9.2.4.3 Class B LLN assignment procedures.48 9.2.4.3.1 PT establishment.48 9.2.4.3.2 FT establishment.49 9.2.5 Link maintenance and information transfer in class B multiple frame operation.49 9.2.5.1 Transmitting I-frames.49 9.2.5.2 Receiving I-frames.50 9.2.5.2.1 P bit set to 1.50 9.2.5.2.2 P bit set to 0.50 9.2.5.3 Sending and receiving acknowledgements.50 9.2.5.3.1 Sending acknowledgements.50 9.2.5.3.2 Receiving acknowledgements.50 9.2.5.4 Receiving REJ-frames.51 9.2.5.5 Receiving RNR-frames.52 9.2.5.6 LAPC own receiver busy condition.53 9.2.5.7 Waiting acknowledgement.53 9.2.5.8 Appropriate supervisory frame.54 9.2.6 Release of class B multiple frame operation.54 9.2.7 Link suspension and resumption.55 9.2.7.1 Link suspension.55 9.2.7.1.1 Class B acknowledged suspend.55 9.2.7.1.2 Unacknowledged suspend.56 9.2.7.2 Class B link resumption.56 9.2.7.3 Connection handover.57 9.2.7.3.1 Class A connection handover.59 9.2.7.3.2 Class B connection handover.59 9.2.7.3.3 Expiry of connection handover timer.60 9.2.8 Re-establishment of class B multi-frame operation.60 9.2.8.1 Criteria for re-establishment.60 9.2.8.2 Procedure.61 9.2.9 Exception handling.61 9.2.9.1 General.61 9.2.9.2 Class B exception condition reporting and recovery.61 9.2.9.2.1 N(S) sequence error.62 9.2.9.2.2 N(R) sequence error.62 9.2.9.2.3 Timer recovery condition.62 9.2.9.2.4 Collision of identical transmitted and received commands.62 9.3 Unacknowledged operation.62 9.3.1 Use of LLN for unacknowledged information transfer.62 9.3.2 Class U link establishment.63 9.3.3 Unacknowledged information transfer.63 9.3.3.1 Transmission of unacknowledged information.63 9.3.3.2 Reception of unacknowledged information.63 9.3.4 Unacknowledged release.63 9.4 Broadcast operation.63 9.4.1 Normal operation.63 9.4.1.1 Procedure in the Fixed radio Termination (FT).63 9.4.1.2 Procedure in the Portable radio Termination (PT).64 9.4.2 Expedited operation.64 9.4.2.1 Procedure in the Fixed radio Termination (FT).64 9.4.2.2 Procedure in the Portable radio Termination (PT).64 9.5 MAC layer interfaces.64 9.5.1 MC-SAP.64 9.5.1.1 C-plane overview.64 9.5.1.2 C-plane service data procedures.65 SIST EN 300 175-4 V1.9.1:2006

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9.5.1.3 U-plane service data.65 9.5.2 MB-SAP.66 9.5.2.1 C-plane service data procedures.66 9.5.2.2 U-plane service data.66 9.5.3 MA-SAP.66 9.5.3.1 Overview.66 9.5.3.2 Service data procedures.67 10 Management procedures.67 10.1 Lower Layer Management Entity (LLME).67 10.2 MAC connection management.67 10.2.1 MAC connection set-up.67 10.2.2 MAC connection release.68 10.2.3 MAC connection modification.68 10.2.4 MAC connection identifiers.69 10.2.4.1 Overview.69 10.2.4.2 Advanced MAC Connection Identifiers (AMCI).69 10.2.4.3 Basic MAC Connection Identifiers (BMCI).70 10.2.4.4 MAC Connection Endpoint Identifier (MCEI).70 10.2.5 Selection of logical channel (CS or CF).70 10.3 DLC C-plane (LAPC) management.70 10.3.1 Provision of link signature.71 10.3.2 Routing of connection oriented links.71 10.3.3 Routing of connectionless links.71 10.4 DLC U-plane (LUX) management.71 10.4.1 U-plane establishment.71 10.4.2 U-plane release.72 10.4.3 U-plane suspend and resume.72 10.5 Connection handover management.72 10.6 Ciphering management.73 10.6.1 Ciphering management in cases where the NWK layer executes the ciphering related MM procedure.73 10.6.1.1 Providing a key to the MAC layer.73 10.6.1.2 Starting and stopping the ciphering.73 10.6.1.3 Connection handover.74 10.6.2 Ciphering management in cases where the NWK layer does not execute the ciphering related MM procedure.74 10.7 Broadband data link management.74 11 U-plane service characteristics.75 11.1 General.75 11.2 LU1 TRansparent UnProtected service (TRUP).75 11.3 LU2 Frame RELay service (FREL).76 11.3.1 General.76 11.3.2 Checksum operation.77 11.3.3 Segmentation and transmission class.77 11.3.4 Data transmission.78 11.3.4.1 Send side procedure.78 11.3.4.2 Receive side procedure.78 11.4 LU3 Frame SWItching service (FSWI).78 11.5 LU4 Forward Error Correction (FEC) service.79 11.6 LU5 Basic Rate Adaption service (BRAT).79 11.6.1 Overview.79 11.6.2 Protected service operation.80 11.6.2.1 General.80 11.6.2.2 Data buffering and initial rate adaptation.81 11.6.2.3 Multi-channel set multiplexing.82 11.6.2.4 Segmentation of Multiplexed Data Units (MDU).83 11.6.2.5 Frame sequencing and addition of control and fill octets.84 11.6.2.6 Frame transmission.85 11.6.3 Unprotected service operation.85 11.6.3.1 General.85 11.6.3.2 Data buffering and initial rate adaption.86 SIST EN 300 175-4 V1.9.1:2006

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11.6.3.3 Multi-channel set multiplexing.86 11.6.3.4 Segmentation of MDUs.87 11.6.3.5 Frame transmission.87 11.7 LU6 Secondary Rate AdapTion (SRAT) service.88 11.7.1 General.88 11.8 LU16 ESCape Service (ESC).89 11.8.1 General.89 11.9 LU7 64 kbit/s data bearer service.89 11.9.1 General.89 11.9.2 Physical layer service.89 11.9.3 MAC layer service.90 11.9.4 DLC layer service.90 11.9.4.1 Architectural model.90 11.9.4.1.1 Transmit (Tx) frame buffering.90 11.9.4.1.2 Receive (Rx) frame buffering.90 11.9.4.2 Automatic-Repeat-Request (ARQ) and Forward Error Control (FEC).90 11.9.4.2.1 Control field.92 11.9.4.2.2 Information field.94 11.9.4.2.3 ARQ checksum.94 11.9.4.3 Procedures for normal operation.95 11.9.4.3.1 Establishment and synchronization procedures.95 11.9.4.3.2 Active phase.97 11.9.4.3.3 Release.98 11.9.4.4 Exceptional procedures.98 11.9.4.4.1 Invalid frame condition.98 11.9.4.4.2 Establishment.99 11.9.4.4.3 Transmitting frames.99 11.9.4.4.4 Receiving frames.99 11.9.4.4.5 Sending acknowledgements.99 11.9.4.4.6 Forwarding of received data.99 11.9.4.4.7 N(R) sequence error.99 11.9.4.4.8 N(O) sequence error.99 11.9.4.4.9 N(S) sequence error.100 11.9.4.4.10 Format error.100 11.9.4.4.11 Abnormal release.100 11.9.4.4.12 Implicit reset.100 11.9.5 Network layer service.101 11.9.5.1 LCE service.101 11.9.5.2 CC service.101 11.10 LU8 service.101 11.10.1 Physical layer service.101 11.10.2 MAC layer service.
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