Table of Contents

Intellectual Property Rights
Foreword
Introduction
1 Scope
2 References
3 Definitions and abbreviations
   3.1 Definitions
   3.2 Abbreviations
4 General
5 Frame structure for peer-to-peer communication
   5.1 General
   5.2 Frame delimitation and fill bits
   5.3 Address field
   5.4 Control field
   5.5 Length field
   5.6 Information field
   5.7 Transparency
   5.8 Format convention
6 Elements of procedures and formats of fields for DL layer
   6.1 General
   6.2 Address field format
   6.3 Address field variables
       6.3.1 Address field extension bit
       6.3.2 Command/Response field bit
       6.3.3 Service Access Point Identifier
       6.3.4 Segmentation indicator bit
       6.3.5 Link protocol discriminator
       6.3.6 Length field indicator
       6.3.7 SST (SACCH status) bit
   6.4 Control field formats
       6.4.1 Information transfer format
       6.4.2 Supervisory format
       6.4.3 Unnumbered format
   6.5 Control field parameters and associated state variables
       6.5.1 Poll/Final bit
       6.5.2 Multiple frame operation - variables and sequence
             numbers
             6.5.2.1 Modulus
             6.5.2.2 Send state variable V(S)
             6.5.2.3 Acknowledge state variable V(A)
             6.5.2.4 Send sequence
             6.5.2.5 Receive state variable
             6.5.2.6 Receive sequence number
             6.5.2.7 Other parameters and variables
             6.5.2.8 Rejected frames sequence numbers Na(R) and
                     Nb(R)
       6.5.3 Unacknowledged operation and parameters
   6.6 Length field format
   6.7 Length indicator field variables
   6.8 Commands and responses
       6.8.1 Information commands
       6.8.2 Set Asynchronous Balanced Mode (SABM) Command
       6.8.3 Disconnect command
       6.8.4 Unnumbered information command
       6.8.5 Receiver ready command/response
       6.8.6 Reject command/response
       6.8.7 Receiver not ready command/response
       6.8.8 Unnumbered Acknowledgement Response
       6.8.9 Disconnect mode response
       6.8.10 Group Reject Command/Response
7 Elements for layer-to-layer communication
   7.1 Definition of primitives and parameters
       7.1.1 Generic names
       7.1.2 Primitives types
       7.1.3 Parameter definition
             7.1.3.1 Message unit
             7.1.3.2 Channel type
             7.1.3.3 Service access point
             7.1.3.4 Release mode
             7.1.3.5 Error cause
             7.1.3.6 Establish mode
             7.1.3.7 Cipher mode indicator CiSyncFlag
             7.1.3.8 Con-Restaurant parameter
             7.1.3.9 SubLayerFlag
             7.1.3.10 LinkStatusFlag
             7.1.3.11 Service Grade
             7.1.3.12 Time to Expiry
   7.2 Primitive procedures
8 Definition of the peer-to-peer protocol LAPSat
   8.1 General
   8.2 General protocol procedures
   8.3 Procedures for unacknowledged information transfer
       8.3.1 General
       8.3.2 Transmission of unacknowledged information
       8.3.3 Receipt of unacknowledged information
   8.4 Procedures for establishment and release of multiple
       frame operation
       8.4.1 Establishment of multiple frame operation
             8.4.1.1 General
             8.4.1.2 Normal establishment procedures
             8.4.1.3 Procedure on expiry of timer T204: normal
                     establishment
             8.4.1.4 Contention resolution establishment procedure
             8.4.1.5 Procedure on expiry of timer T204: contention
                     resolution (MES only)
       8.4.2 Information transfer
             8.4.2.1 General requirements
             8.4.2.2 Error conditions
             8.4.2.3 Fill frames
       8.4.3 Suspension and resumption of multiple frame operation
             8.4.3.1 General
             8.4.3.2 Suspension
             8.4.3.3 Resumption
       8.4.4 Termination of multiple frame operation
       8.4.5 Idle state
       8.4.6 Collision of unnumbered commands
   8.5 Procedure for information transfer in multiple frame operation
       8.5.1 Transmitting I frames
       8.5.2 Receiving I frames
             8.5.2.1 I Frame received with P = 1
             8.5.2.2 I Frame received with P = 0
             8.5.2.3 Receiving frames for SAPI = 2 on the network end
       8.5.3 Receiving acknowledgment
             8.5.3.1 Piggybacked acknowledgment
             8.5.3.2 Piggybacked acknowledgment with a command frame
       8.5.4 Receiving a GREJ frame
             8.5.4.1 DL receives GREJ during timer recovery and
                     normal conditions
             8.5.4.2 DL receives GREJ while transmitting a frame
       8.5.5 Reception of RNR
       8.5.6 DL layer own receiver busy
       8.5.7 Waiting acknowledgment
       8.5.8 Performance Considerations
   8.6 Abnormal release and reestablishment of multiframe operation
       8.6.1 Criteria for reestablishment
       8.6.2 Criteria for abnormal release
       8.6.3 Procedures for reestablishment
       8.6.4 Procedures for abnormal release
   8.7 Exception condition reporting and recovery for multiple
       frame operation
       8.7.1 N(S) sequence error
       8.7.2 Timer recovery
       8.7.3 Invalid frame condition
       8.7.4 N(R) sequence error
       8.7.5 Na(R) or Nb(R) sequence error
       8.7.6 Layer 3 message with incorrect length
   8.8 List of system parameters
       8.8.1 Timer T200
       8.8.1.1 For SAPI = 0, SAPI = 2 and SAPI = 3
       8.8.2 Maximum number of retransmissions (N200)
       8.8.2.1 For SAPI = 0, 2, and 3
       8.8.3 Maximum number of octets in an I, UI, SABM, and UA
             frame information field (N201)
       8.8.4 Void
       8.8.5 Maximum number of outstanding I frames (k)
       8.8.6 Maximum number of octets in a layer 3 message
       8.8.7 Maximum number of SABMs in a group (N204)
       8.8.8 Timer T204
       8.8.9 Time to expiry (T205)
9 Special protocol operation on SAPI = 0 and SAPI = 3
10 DL layer FRAME formats
   10.1 Data link layer I-frame
   10.2 Data link layer S frame format (except GREJ)
   10.3 Data link layer GREJ frame
   10.4 Data link layer U frames format
Annex A (normative): Random access procedure
Annex B (normative): Handling of frames with parameter errors
      B.1 General
      B.2 Parameter error in the address field
          B.2.1 Invalid SAPI
          B.2.2 Wrong value of the C/R bit
          B.2.3 SI bit error
          B.2.4 Length field indicator error
      B.3 Parameters errors in the control field
      B.4 Parameters errors for length field
          B.4.1 Supervisory frames
          B.4.2 Unnumbered frames
          B.4.3 Information frames
Annex C (normative): Transmission of voice, FACCH and SACCH frames
        on TCH3
History

Abstract

Describes the Link Access Procedures (LAP) for the Satellite Channel (LAPSat).

General Product Information

Published
Document Type	Standard
Status	Current
Publisher	European Telecommunications Standards Institute
Pages
ISBN
Committee	SES GMR