1、. TIAIEIA TELECOMMUNICATIONS SYSTEMS BULLETIN Enhanced Digital Access Communications System (EDACS) Land Mobile Radio System Packet Data Specification TSB69.1-2 APRIL 1999 TELECOMMUNICATIONS INDUSTRY ASSOCIATION Electronic Industries Alliance Copyright Telecommunications Industry Association Provide
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8、re revisions of this Bulletin are encouraged to do so. It is the intention of the formulating committee to revise and update this Bulletin from time to time as may be occasioned by changes in technology, industry practice, or governent regulations, or for other appropriate reasons. (From Project No.
9、 4406, formulated under the cognizance of the TIA TR-8.5 Subcommittee on Signaling and Data Transmission.) Published by TELECOMMUNICATIONS INDUSTRY ASSOCIATION 1999 Standards and Technology Department 2500 Wilson Boulevard Arlington, VA 22201 PRICE: Please refer to the current Catalog of ELECTRONIC
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11、o reproduction or networking permitted without license from IHS-,-,-STD-EIA TSBbS-1-2-ENGL 1777 3234b b14080 778 TIAIEIAITSB69.1-2 TABLE OF CONTENTS 1 . INTRODUCTION . i 1.1 Revision History . 1 1.2 References . 1 1.3Document Scope 2 2 . PACKET SWITCHED DATA . 4 2.1 General Description . 4 2.1.1 Mob
12、ile to Fixed Host Service . 5 2.1.2 Mobile to Mobile RDI Data Service 9 2.1.3 Mobile to Mobile Gateway Data Service 11 2.2MDTlMRC Interface (A) 12 2.2.1 Layer 1 13 2.2.2 Layer 2 15 2.2.3 Layer 3 . The wireless link of the connection is between a Mobile Routing/Control (MRC) and a BSS (or base statio
13、n system, comprising one or more base stations). In addition to the base station(s), the radio subnetwork FNE comprises switching facilities, control facilities, and interworking / gateway functions (System Gateway). The System Gateway (SysG) either routes RDI packets between radio subnetworks and i
14、ts components including the MDT and the ES or performs an ENL (EDACS Network Layer, reference Appendix F) translation on 5 Copyright Telecommunications Industry Association Provided by IHS under license with EIANot for ResaleNo reproduction or networking permitted without license from IHS-,-,-STD-EI
15、A TSBbS-L-2-ENGL 1999 3234bUll Ub14089 7T5 TINEIAITSB69.1-2 IP datagrams generated by the MDT and the IP-connected ES(s) and then routes the resulting RDI packets between radio subnetworks and its components. BEARER SERVICE ACCESS POINTS ENL I ENL RDI Y I EDACS Signaling +I+ EIAITIA 232-! examines t
16、he destination address field in the modified IP header. For either RDI or IP data units, the SysG next examines its routing table to determine where to forward the packets. At this point the SysG functions as any standard IP router which conforms to “Requirements for Internet Gateways“ RFClOO9. If t
17、he destination of the data unit is an ES or another SysG, the SysG invokes either the services of the Ethernet driver (Ed) or RDI (A) to deliver the packet. 8 Copyright Telecommunications Industry Association Provided by IHS under license with EIANot for ResaleNo reproduction or networking permitted
18、 without license from IHS-,-,-TINEIA/TSB69.1-2 If the destination is another MDT as described in section 2.1.3, the SysG reverses the process thus described by building a DAI frame destined for the MRC connected to the destination MDT and submitting the frame to the System for actual delivery to the
19、 MRC. When the MRC receives the DAI frame it extracts the IP datagrams and forwards it to the MDT via the “A“ interface. 2.1.2 Mobile to Mobile RDI Data Service Figure 2.3 shows a Mobile Data Peripheral (MDT) communicating with another MDT or with an ES via a message switch in the System. Here, both
20、 bearer service access points are reference points “A“. This packet data service is standard for an EDACS system. The wireless link of the connection is between a Mobile RoutingControl (MRC) and a BSS (or base station system, comprising one or more base stations). Here it is assumed that the base or
21、 FNE facilities have little if any switching, routing, or location tracking capability. 2.1.2.1 Message Switch A message switch is necessary to provide a connection to a host or server. The message switch enables the host computer to communicate with an EDACS system by converting protocols when the
22、hosts protocol differs from RDI. Another function of the message switch is to determine the proper path to and from the host; for example, in circumstances when there are multiple transmitting or multiple receiving control stations (MRs). All attached hosts must be identified by port IDS between 1 a
23、nd 63. The initiating MDT must identify the address of the destination unit. A port ID is a special kind of logical ID which identifies the MRCs associated with the host computer. Mobile data systems may have many MDTs communicating with a single host computer, which may have multiple ports connecte
24、d to RDIs. MRCs associated with hosts must use port addresses rather than logical addresses for this reason. Each MDT has access to 63 different hosts. 2.1.2.2 Radio Data Interface The A interface consists of a serial interface between the MDT and MRC. The protocols at OS1 layers 1 and 2 are TINEIA-
25、232-E and the Radio Data Interface (RDI) protocol respectively. RDI is a protocol or level converter which interfaces between a Mobile Data Terminal (MDT) and a MRC or a Message Switch and Control Stations. Additional detail on the RDI can be found in section 2.2. 9 Copyright Telecommunications Indu
26、stry Association Provided by IHS under license with EIANot for ResaleNo reproduction or networking permitted without license from IHS-,-,-STD-EIA TSBbSmL-Z-ENGL 1779 = 3234b00 Ob14073 32b 9 TINEIA/TSB69.1-2 BEARER SERVICE ACCESS POINTS RDI RDI RDI DAI p DAI TlA-232-Ebi RDI + A + A + A . Messag Switc
27、h 4 El Figure 2.3. Mobile To Mobile RDI Data 2.1.2.3 Service Setup Procedures Before any user messages can be conveyed by the packet bearer service, it is necessary to configure the MDT and MRC. Specifically, the RDI connection between the MDT or message switch and the MRC must be opened and the MRC
28、 must be placed in Data mode. Once the configuration has been completed, RDI packets can be sent in both directions amongst all MDTs in range of the repeater. 2.1.2.4 Data Transfer Once the setup outlined in section 2.1.2.3 has been performed, RDI packets can be sent and received by mobile hosts. Th
29、is section will trace a data transfer between MDTs or between MDTs and the ES. A segment of information or message is generated by a higher layer protocol (transport or application) in the MDT which invokes the RDI software to build and deliver an RDI packet to the ultimate destination. The MDT appl
30、ication is “bound“ to the optional EDACS API (Application Programming Interface) CommServB software which executes all commands required by the RDI protocol for the MDT to send and receive data via the MRC. The RDI software in the MDT has a default route which specifies the MRC as the node to which
31、all 10 Copyright Telecommunications Industry Association Provided by IHS under license with EIANot for ResaleNo reproduction or networking permitted without license from IHS-,-,-STD-EIA TSBbS-L-Z-ENGL L477 3234b00 Ob14074 2b2 D TINEIAlTSB69.1-2 outgoing packets should be forwarded. This route also s
32、pecifies the MDTs “A“ reference point as the interface via which it can reach the MRC. The RDI software in the MDT thus hands the packet to the RDI driver for delivery to the MRC. At the MRC, the RDI driver receives the packet and passes it to the DAI. The MRC, examines the destination address in th
33、e RDI header and determines the appropriate MRC to which the DAI frame must be forwarded. This MRC may belong to the ES or another MDT. 2.1.3 Mobile to Mobile Gateway Data Service Figure 2.4 shows a Mobile Data Peripheral (MDT) communicating with another MDT via a System Gateway in the System, b- BE
34、ARER SERVICE ACCESS POINTS ENL 4 RDI RDI RDI TIA-232-E DAI DAI b w Figure 2.4. Mobile to Mobile Gateway Data Here, both bearer service access points are reference points “A. The wireless link of the connection is between a Mobile Routing/Control (MRC) and a BSS (or base station system, comprising on
35、e or more base stations). Here it is assumed that the FNE facilities have switching, routing, and location tracking capability. 2.1.3.1 Radio Data Interface The A interface consists of a serial interface between the MDT and MRC. The protocols at OS1 layers 1 and 2 are TINEIA-232-E and the Radio Data
36、 Interface (RDI) protocol respectively. Layer 3 is the EDACS Network Layer (reference 11 Copyright Telecommunications Industry Association Provided by IHS under license with EIANot for ResaleNo reproduction or networking permitted without license from IHS-,-,-TINEINTSB69.1-2 Appendix F) which transf
37、orms the IP header before it is delivered to the RDI data link layer for delivery. RDI is a protocol or level converter which interfaces between a Mobile Data Terminal (MDT) and a MRC. 2.1.3.2 Service Setup Procedures Before any user messages can be conveyed by the packet bearer service, it is neces
38、sary to configure the MDT and MRC. Specifically, the RDI connection between the MDT and the MRC must be opened and the MRC must be placed in Data mode. Once the configuration has been completed, IP datagrams can be sent in both directions amongst all MDTs in range of the repeater. 2.1.3.3 Data Trans
39、fer Once the setup outlined in section 2.1.2.3 has been performed, IP datagrams can be sent and received by mobile hosts. This section will trace a data transfer from one MDT to another. A segment of information or message is generated by a higher layer protocol (transport or application) in the MDT
40、 which invokes the optional END (EDACS Network Driver) software to build and deliver an RDI packet to the ultimate destination. The MDT IP application is “bound“ to the EDACS API (Application Programming Interface) END which executes all commands required by the RDI protocol and serves as a DOS-Ethe
41、rnet device driver for the MDT to send and receive data via the MRC to hosts located on Ethernet LANs. The END software in the MDT has a default route which specifies the MRC as the node to which all outgoing packets should be forwarded. This route also specifies the MDTs “A reference point as the i
42、nterface via which it can reach the MRC. The END driver in the MDT hands the packet to the RDi data link layer driver for delivery to the MRC. At the MRC, the RDI driver receives the packet and forwards them, with the enhanced IP header, to the System Gateway. The System Gateway examines the destina
43、tion address in the RDI header and determines the appropriate MRC to which the DAI frame must be forwarded. 2.2 MDT/MRC Interface (A) The MDT/MRC interface (reference point “A) is depicted in Figure 2.5. The A interface consists of a serial interface between the MDT and MRC. The protocols at OS1 lay
44、ers 1 and 2 are ElMIA-232 and RDI respectively. In the case of IP, Layer 3 is the EDACS Network Layer which is covered in Appendix F. Whereas the scope of the A interface is confined to the lowest three layers of the OS1 Reference Model, other protocols are shown in Figure 2.5 to provide an 12 Copyr
45、ight Telecommunications Industry Association Provided by IHS under license with EIANot for ResaleNo reproduction or networking permitted without license from IHS-,-,-STD-EIA TSBb7.1-2-ENGL 1999 m 323Lib00 ObL407b 035 m TINEINTSB69.1-2 MDP . enhanced perspective. The lower three layers are described
46、in the subsequent sections. 7 4-6 3 2 1 5-7 EDACS Network Layer 232-E Figure 2.5 MDT/MRC Interface 2.2.1 Layer 1 The “A“ interface at the physical layer (OS1 layer 1 ) uses a subset of the signals defined for the DTE/DCE data interface by EIA/TIA-232-E and CCITT V.24. The voltage levels defined in t
47、hese specifications are recommended (i.e., ON = +3 volts or greater, OFF = -3 volts or more negative). Conformance to physical connector specifications of EINTIA-232-E are not required. Reference Appendix B for the connector specification. This signal subset comprises the following: V.24 E IAKIA-232
48、-E Description 102 AB Common 103 BA Transmitted Data (TD) 104 BB Received Data (RD) 107 CC Data Set Ready (DSR) 133 CJ Ready for Receiving (RFR) 106 DB Clear to Send (CTS) The following additional signals are optional: Direct ion Both DCE Input DCE Output DCE Output DCE Input DCE Output V.24 EIAKIA-
49、232-E Description Direct ion 108 CD Data Terminal Ready (DTR) DCE Input 113 DA Transmit Data Clock (TDC) DCE Input 115 DD Receive Data Clock (RDC) DCE Output 13 Copyright Telecommunications Industry Association Provided by IHS under license with EIANot for ResaleNo reproduction or networking permitted without license from IHS-,-,-STD*EIA TSBbS.L-2-ENGL 1777 3234b00 ObLLi077 T7L TINEIEVTSB69.1-2 The functionality of
