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Presentation to TETRA BUSINESS SYSTEMS GROUP AN INTRODUCTION TO THE PEI

Presentation to TETRA BUSINESS SYSTEMS GROUP AN INTRODUCTION TO THE PEI. Nick Smye 15 February 2000. Concepts to Reality. e-mail: masoncom@masoncom.com. www.masoncom.com. FORMAT. 1. Introduction to Mason Communications 2. Radio Peripheral Interfaces 3. PEI Overview 4. AT Command Set

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Presentation to TETRA BUSINESS SYSTEMS GROUP AN INTRODUCTION TO THE PEI

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  1. Presentation toTETRA BUSINESS SYSTEMS GROUPAN INTRODUCTION TO THE PEI Nick Smye 15 February 2000 Concepts to Reality e-mail: masoncom@masoncom.com www.masoncom.com

  2. FORMAT 1. Introduction to Mason Communications 2. Radio Peripheral Interfaces 3. PEI Overview 4. AT Command Set 5. PPP/TNP1 Command Set 6. Current Status of PEI 7. Conclusion

  3. INTRODUCTION TOMASON COMMUNICATIONS • Telecoms and IT Consultancy • What is our TETRA Experience? • Worked with Home Office on PSRCP since 1994 • Business Case Phase • Project Definition Study Invitation to Tender • User Service Level Requirements • Project Definition Study Phase • Greater Manchester Police - Business drivers for TETRA • Terminal & Peripheral Equipment • Integrated TETRA Radio & Telephony

  4. INTRODUCTION TOMASON COMMUNICATIONS • Lancashire Constabulary - Pilot Assurance Support • States of Jersey Police • Validation of pilot system • Re-validation after upgrade • European GSM Operator – assistance with RFP to support a Public TETRA Licence Bid • Technical Advisers to PITO

  5. RADIO PERIPHERAL INTERFACESRadios and Peripherals • In early days (pre-trunked), professional radios tended to be specialised and expensive • Peripherals limited and manufacturer specific • Remote microphone • Earphones/Headsets • Speakers • Some peripheral specialists • Products ordered to a specific interface (££ + time) • E.g. Handsfree mic (e.g. Sonic)

  6. RADIO PERIPHERAL INTERFACES Trunked Radio • Introduction of trunking with standard and open systems (MPT 1327/MPT1343) • Radio offers access to powerful new functionality (speech+ status/short data/data) • System performs Dynamic Channel allocation • Applications are now able to to use these features…plus access to radio • BUT.. How do we access these features in a non-proprietary manner?

  7. RADIO PERIPHERAL INTERFACES MAP27 Interface Standards • Initially some manufacturers used proprietary interfaces • Applications manufacturer specific • Fleets with more than one manufacturer • Open standard, MAP27, published in 1992 • Most manufacturers support it • Defined interface (RX,TX GND) and Layered Protocol • Data Link Layer uses a block format, delimited by control characters • Allows simultaneous operation (e.g. RSSI check during a data call) ESI Case

  8. RADIO PERIPHERAL INTERFACES MAP27 Network Layer Data Link Layer Blocks delimited by Control Characters Provides Block Transport Terminal Radio Network Layer Data Link Layer Physical Layer Status Short Data Voice and NPD Modem Call Connection Clear Diversion Radio Control

  9. RADIO PERIPHERAL INTERFACES What is the GSM Approach? Base GSM GSM 07.07 GSM 07.05 SMS GSM 07.60 GPRS All AT command Based Call Control Network Service Mobile Equipment Control and Status AT and Block Message Retrieval and Transmission Hex Encoded Binary Block mode – similar to MAP27 PPP command Based X25 PPP IHOS AT PPP Dial In Compatibility

  10. PEI OVERVIEWTETRA – Open Standards Based Architecture I4’ I6 Network Management I4 I2 I5 I1 I3 TETRA 1 TETRA 2 DEFINED INTERFACES I1 Radio air interface I2 Line station interface I3 Inter-system Interface I4 Terminal equipment interface (MS & TE) I4’ Terminal equipment Interface (LS & TE) I5 Network Management Interface I6 Direct Mode radio air interface NSS BSS PSTN PTN ISDN PDN OMC GATEWAYS

  11. PEI OVERVIEW Peripheral Equipment Interface • Defined Standard for access to: • Data • Set-up and Control of Voice Calls • Radio Specifics (e.g. battery status) • User Applications in Radio • Standard Physical Interface (?) • Minimal Extra Software in Terminal ( Driver) • Max compatibility with GSM • Still in draft

  12. PEI OVERVIEW Physical Connection • Physical layer V24/V28 • D type (RX,TX,GND) • RJ11/RJ45 • Other Serial Form Physical Layers can be used where Appropriate • Infrared (GSM?) • Ethernet • Bluetooth?

  13. PEI OVERVIEW PEI PROTOCOLS PEI PROTOCOLS AT Commands PPP Commands Radio Remote Control Packet Data Short Data Circuit Mode Data Radio Functions IPv4 IPv6 Speech CC SDS Radio Config & Status Supplementary Services CM Data

  14. AT COMMAND SETCommands • AT Commands well known in Industry • “+C” prefix reserved for Digital Cellular • PEI AT Commands Based on: • Cellular DCE Control • PCCA Wireless Modems • TETRA Specific • SDS (very similar to GSM) • Radio Control

  15. AT COMMAND SETTypical Applications • Those suited to small data transfers using TETRA SDS • Type 1 – 16 bit • Type 2 – 32 bit • Type 3 – 64 bit • Type 4 – up to 2039 bits (Advanced Link recommended for user data longer than approx. 133 Octets) • Short Data Transfer Layer (SDS-TL) • Built on top of SDS Type 4 • Provides end to end acknowledgment • Store and Forward • Typical Application - AVL ARDxx: voice in GSM – audio routing man specific

  16. AT COMMAND SETLimitations • Terminal is either in Command State or On-line Data State • In On-line Data state, no other communication with radio is possible (e.g. battery state) • Usefulness is limited to SDS, Circuit Mode Data • What support for CM data? • No current support for voice calls

  17. AT COMMAND SETAdvantages • Simple to implement • No need for TCP/IP stack and PPP layer • Reduces terminal’s complexity, memory requirement • Reduced Power consumption • Easy to debug

  18. PPP/TNP1 COMMAND SETWhat is PPP? • Point-to-Point Protocol • Standard Internet (IETF) Open Protocol • Standard method of transporting multi-protocol datagrams over point-to-point links • Method for encapsulating multi-protocol datagrams • Link Control Protocol for establishing, configuring and testing the link • Family of Network Control Protocols for establishing and configuring the Network Protocols that run over PPP • THE standard for PCs for dialup internet (IP) access

  19. PPP/TNP1 COMMAND SET PPP Frames FCS Frame End Frame Start Protocol DATA Padding • 0xC021 Link Control Protocol – establishes, maintains and ends PPP • 0x0021 IP Protocol • 0x8021 Internet Protocol Control Protocol – establishes configuresand terminates the TCP/IP session • 0x0287 TETRA Network Protocol 1 • 0x8287 TETRA Network Protocol 1 Control Protocol

  20. PPP/TNP1 COMMAND SET PPP Mode Structure User Terminal RADIO RADIO CONTROL DATA TNP1CP Network Layer TCP/IP TNP1 Data Link Layer PPP Frame PPP Frame PPP Frame IPCP PPP PPP LCP RS232

  21. PPP/TNP1 COMMAND SET IP Protocol • IP provides the means of transporting the application data • IP is universally used • IPv4 and IPv6 Supported by PEI Specification • Provides for standard interconnection at the SwMI to external IP networks (e.g. host computer) via router/gateway • BUT not as efficient as SDS for transfer of short messages

  22. PPP/TNP1 COMMAND SET TNP1 Protocol • This provides the means of setting up calls and controlling the radio • No equivalent functionality in existing Internet Specifications and so this is unique to TETRA • Uses standard PPP frames with a TNP1 Protocol number (0x0287)

  23. PPP/TNP1 COMMAND SET TNP1 Commands • Radio Control and Call set-up • Priority • Group Attachment • SDS • Duplex/half duplex • Energy Saving Mode • Etc. • Allows proprietary defined information to be sent and received from radio

  24. PPP/TNP1 COMMAND SET TETRA PEI PPP Issues • PPP must be used for TETRA Packet Data Services • No manufacturers are currently supporting IP packet data • PPP/TNP1 complex to implement in radio and terminal • Memory • Power consumption • Development effort

  25. CURRENT STATUS OF PEI • Still under draft • Complex standard – TETRA MOU have proposed a subset of the AT commands • PPP/TNP1 support awaiting rollout of Packet Data? • What is the current level of support? • Are all manufacturers going to support it? • Will the widespread adoption of GPRS influence TETRA?

  26. CONCLUSION • PEI Standard defined for TETRA Terminals • AT and PPP modes • AT simple and suited to small data requirements • PPP complex but powerful – the only choice for packet data • What is the support from the manufacturers and the timescales?

  27. Military • No access to CODEC • SDS-TL • IP overhead vs SDM? • AT/Radio turnon • Suppl Serv? • Voice call using AT? • IP When

  28. CASE STUDY -Public Safety Radio Communications Project • Business Case Phase • Evaluation of suitable systems • Technical input to Business Case • Project Definition Study Invitation to Tender • Functional Specification • Terms of Reference • User Service Level Requirements • Service Level Template and Guide • Project Definition Study Phase • Ongoing review of Study Products • Review of FDS and Operational Trials.

  29. PUBLIC SAFETY RADIO COMMUNICATIONS (PSRCP) PROJECT • Home Office - Technical Advisers • Greater Manchester Police - Business drivers for TETRA • Lancashire Constabulary - Pilot Assurance Support • Terminal & Peripheral Equipment • Integrated TETRA Radio & Telephony • Hampshire Police - Impact of PSRCP Appraisal • Cheshire Constabulary - Assurance Support.

  30. PUBLIC SAFETY RADIO COMMUNICATIONS (PSRCP) PROJECT • Home Office - Technical Advisers • Greater Manchester Police - Business drivers for TETRA • Lancashire Constabulary - Pilot Assurance Support • Terminal & Peripheral Equipment • Integrated TETRA Radio & Telephony • Hampshire Police - Impact of PSRCP Appraisal • Cheshire Constabulary - Assurance Support.

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