Proposed ISSI Enhancements for Packet Data Service

1
Proposed ISSI Enhancements for Packet Data Service

• Jim Eastwood
• Motorola
• May 11, 2006

2
Introduction

• When adding P25 Packet Data to Trunked ASTRO25
  systems, an early problem faced by Motorola was
  how to add Packet Data Service while leveraging
  the work the went into providing Trunked Voice
  Services
• PSAWG faces a similar challenge in that the scope
  1 ISSI has been defined for Trunked Voice
  Services and the scope 2 ISSI needs to add Packet
  Data Service
• Motorola sees value in leveraging as much of the
  scope 1 ISSI work as possible for the scope 2
  ISSI
• Motorola proposes that a Packet Data ISSI
  architecture based on the scope 1 ISSI is viable
  and will discuss the specifics later in this
  slide deck

3
TIA-102.BACA ISSI Standard

• Currently Describes the Architecture, Protocol
  Suite, Messages, Parameters, State Models, and
  Procedures for the Scope 1 Services and Functions
  that follow
• Trunked Voice Services
• Group Voice Service for both Confirmed and
  Unconfirmed Group Calls
• SU-to-SU Voice Service for both Direct Calls and
  Calls Requiring Prior RF Availability Check
• Trunked Mobility Management Functions
• SU Registration
• SU Tracking
• Group Affiliation
• Group Tracking
• Authentication Credential Distribution

4
Typical System Model Depicting ISSI (G Interface)
Model from TIA-102.BACA Figure 1
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ISSI Protocols

• The ISSI Employs Two Distinct Protocol Suites
• The SIP Protocol is used for Mobility Management
  and Call Control
• The RTP Protocol is used for Arbitration of
  Individual Talk-spurts within a Call and
  Conveyance of Voice between RFSSs
• The ISSI Protocols Operate on top of UPD and IP

Model from TIA-102.BACA Figure 21
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ISSI SAP Model and Transactions
Model from TIA-102.BACA Figure 15
Model from TIA-102.BACA Figure 16
7
ISSI MM and CC SAP Functions/Primitives
TIA-102.BACA Table 1
TIA-102.BACA Table 2
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Packet Data ISSI Architecture

• Based on ISSI Scope 1 (TIA-102.BACA)
• Uses Same ISSI Protocols (SIP, RTP, SAP Model,
  etc.)
• Uses ISSI CC Procedures to support Packet Data
  Service Context Management
• CC Procedures require minor extensions
• SU Must Be Registered (Unit Registration) Prior
  to Trunked Packet Data Service Context Activation
  and Must Deactivate All Contexts if Deregistered
• Packet Data Traffic Is Routed Through Home RFSS
• Same as Voice Traffic
• Terminate SNDCP Tunnel in Home RFSS
• SNDCP Packets Encapsulated in RTP
• Home RFSS Controls Packet Data Supplementary
  Services and Provisioned Parameters
• No Impact to Current Packet Data Capable SU

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ISSI Scope 1 Enhancements for Packet Data Service

• Enhance CC Procedures for Context Management
• New CC_Context transaction
• Extend SIP CC and MM Messages
• Transport SNDCP encapsulated Packet Data over
  ISSI using RTP
• Path established as part of CC procedures
• Define RTP block type for SNDCP Data

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Inter-RFSS Register/Context Activation
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Inter-RFSS Register/Context Activation
MM_Registration.Ind
REGISTER
MM_Registration.Rqst
200 OK
MM_Registration.Resp
MM_Registration.IResp
CC Transaction for Context Management similar to
Unit to Unit Call
CC_Context.Ind
INVITE
CC_Context.Rqst
200 OK
CC_Context.Resp
CC_Context.IResp
ACK
CC_Context.IRConf
CC_Context.Conf
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Inter-RFSS Context Handover
13
Inter-RFSS Context Handover
MM_Registration.Ind
REGISTER
MM_Registration.Rqst
200 OK
MM_Registration.Resp
MM_Registration.IResp
REGISTER
MM_Roamed.Rqst
MM_Roamed.Ind
MM_Roamed.Resp
200 OK
MM_Roamed.IResp
CC_Context.Ind
INVITE
CC_Context.Rqst
CC_Context.Resp
200 OK
CC_Context.IResp
CC_Context.IRConf
ACK
CC_Context.Conf
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Benefits of Proposed Architecture

• Simple Extension to ISSI Scope 1 Messages and
  Procedures Already Defined and Balloted
• RFSS Packet Data Mobility Independent of IP
  Version
• Does not introduce any additional IP migration
  issues
• User Packet Data Applications Unaffected by RFSS
  Handoff
• Air Interface Independent
• FDMA, TDMA, 2-slot, 4-slot
• Leverages SNDCP already defined in TIA.102
  standard
• Also in TETRA, GPRS, and TIA.902 (Wideband)
  standards

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Summary

• No IPR Issues
• ISSI Messages and Procedures Largely Already
  Defined in TIA-102.BACA standard
• Packet Data Leverages Voice Architecture
• No Additional Impact on IPv4 to IPv6 Migration
• No Dependency on Mobile IP Version

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Backup
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TIA-102.BACA Notes

• The ISSI (G Interface) Enables Interoperability
  between RFSSs of Various Manufacturers in a Wide
  Area Network
• The ISSI Supports the Interface Between two
  RFSSs
• within the same P25 system
• in two separate P25 systems in the same WACN
• in two separate P25 systems with different WACNs
• Mobility Management (MM) Functional Service
  employs SIP and is for (see section 2.1.3.1)
• SU Registration
• SU Tracking
• SU Roaming
• SU Authentication
• Call Control (CC) Functional Service employs SIP
  and is for call control signaling between RFSSs
  at set up and at call release (see section
  2.1.3.2)
• Transmission Control (TC) Functional Service
  employs RTP and is for (see section 2.1.3.3)
• PTT management of competing talk-spurts
• Conveyance of voice information and other
  signaling between RFSSs

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TIA-102.BACA Notes
Model from TIA-102.BACA Figure 9
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Additional Packet Data ISSI Details

• Use Same ISSI Protocols (summarized on slide 5)
• Use SIP for Packet Data MM and CC
• Use RTP for Packet Data Transport
• Packet Data Service Context Management Functions
• Activation
• Deactivation
• Handover
• Home RFSS Controls Packet Data Services and
  Provisioned Parameters
• Interfaces to DHCP, AAA, Customer Network, etc.
• APN (could be index or string or provisioned)
• Supplementary Services (user authentication,
  compression, etc.)