1、 TSB-69.1-2 April 1999 (r 4/2009) Enhanced Digital Access Communications System (EDACS) Land Mobile Radio System PacketData Specification NOTICETIA/EIA Engineering Standards and Publications are designed to serve the public interestthrough eliminating misunderstandings between manufacturers and purc
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8、ect No. 4406, formulated under the cognizance of the TIA TR-8.5 Subcommittee onSignaling and Data Transmission.)Published byTELECOMMUNICATIONS INDUSTRY ASSOCIATION 1999Standards and Technology Department2500 Wilson BoulevardArlington, VA 22201PRICE: Please refer to the current Catalog ofELECTRONIC I
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11、MMUNICATIONS SYSTEMS BULLETIN Enhanced Digital Access Communications System (EDACS) Land Mobile Radio System Packet Data Specification TSB69.1-2 March 24, 1999 Copyright, Ericsson, Inc. , 1995 Mountain View Road, Lynchburg, VA 24502 A free irrevocable license is granted to the Telecommunications Ind
12、ustry Association (TIA) to incorporate text contained in this contribution and any modifications thereof in the creation of a TIA standards publication; to copyright in TIAs name any TIA standards publication even though it may include portions of this contribution; and at TIAs sole discretion to pe
13、rmit others to reproduce in whole or in part the resulting TIA standards publication. TELECOMMUNICATIONS INDUSTRY ASSOCIATIONTHIS PAGE LEFT INTENTIONALLY BLANK TIA/EIA/TSB69.1-2 i TABLE OF CONTENTS 1. INTRODUCTION.1 1.1 Revision History .1 1.2 References.1 1.3 Document Scope2 2. PACKET SWITCHED DATA
14、.4 2.1 General Description .4 2.1.1 Mobile 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 2.2 MDT/MRC Interface (A) .12 2.2.1 Layer 113 2.2.2 Layer 215 2.2.3 Layer 3 examines the destination address field in the modified IP header.
15、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“ RFC1009. If the destination of the data unit is an ES or another SysG
16、, the SysG invokes either the services of the Ethernet driver (Ed) or RDI (A) to deliver the packet. 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 submitt
17、ing the frame to the System for actual delivery to the MRC. When the MRC receives the DAI frame it extracts the IP datagrams and forwards it to the MDT via the “A“ interface. TIA/EIA/TSB69.1-2 9 2.1.2 Mobile to Mobile RDI Data Service Figure 2.3 shows a Mobile Data Peripheral (MDT) communicating wit
18、h another MDT or with an ES via a message switch in the System. Here, both 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 Routing/Control (MRC) and a BSS (or base station system,
19、 comprising one or more base stations). Here it is assumed that the base or 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 com
20、puter to communicate with an EDACS system by converting protocols when the 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 st
21、ations (MRs). All attached hosts must be identified by port IDs between 1 and 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 commun
22、icating with a single host computer, which may have multiple ports connected 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 interfa
23、ce between the MDT and MRC. The protocols at OSI layers 1 and 2 are TIA/EIA-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
24、 on the RDI can be found in section 2.2. TIA/EIA/TSB69.1-2 10 BSS = (BR + BA + BRC)RDITIA-232-EAUmMDT MRC MRBSSRF SubnetworkRDITIA-232-EAUmMessageMRCMRBEARER SERVICE ACCESS POINTSRDIAUmMDT MRC MRDAIRDIDAISwitchESFigure 2.3. Mobile To Mobile RDI Data 2.1.2.3 Service Setup Procedures Before any user m
25、essages 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 must be placed in Data mode. Once the configuration has been completed, RDI packets can be sen
26、t 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. This section will trace a data transfer between MDTs or between MDTs and the ES. A segment of inf
27、ormation 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 application is “bound” to the optional EDACS API (Application Programming Interface) CommServ softw
28、are 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 all TIA/EIA/TSB69.1-2 11 outgoing packets should be forwarded. This route also specifies the MDT
29、s “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 the RDI header and
30、 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. BSS = (BR + BA + BRC)
31、RDITIA-232-EAUmMDT MRC MRBSSRF SubnetworkUmSystemSystemBEARER SERVICE ACCESS POINTSRDIAUmMDT MRC MRDAIRDIDAIGatewayControllerENLENLFigure 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 Routi
32、ng/Control (MRC) and a BSS (or base station system, comprising one 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 pr
33、otocols at OSI layers 1 and 2 are TIA/EIA-232-E and the Radio Data Interface (RDI) protocol respectively. Layer 3 is the EDACS Network Layer (reference TIA/EIA/TSB69.1-2 12 Appendix F) which transforms the IP header before it is delivered to the RDI data link layer for delivery. RDI is a protocol or
34、 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 necessary to configure the MDT and MRC. Specifically, the RDI connection between the MDT and the MRC must be
35、 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 Transfer Once the setup outlined in section 2.1.2.3 has been performed, IP datagrams can be sent and receive
36、d 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 which invokes the optional END (EDACS Network Driver) software to build and deliver an RDI packet to t
37、he 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-Ethernet device driver for the MDT to send and receive data via the MRC to hosts located on Ethernet LANs.
38、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 interface via which it can reach the MRC. The END driver in the MDT hands the packet to the RDI data li
39、nk 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 destination address in the RDI header and determines the appropriate MRC to which the DAI frame must be forwa
40、rded. 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 OSI layers 1 and 2 are EIA/TIA-232 and RDI respectively. In the case of IP, Layer 3 is the EDACS Network Lay
41、er which is covered in Appendix F. Whereas the scope of the A interface is confined to the lowest three layers of the OSI Reference Model, other protocols are shown in Figure 2.5 to provide an enhanced perspective. The lower three layers are described in the subsequent sections. TIA/EIA/TSB69.1-2 13
42、 MDP MRC232-EEDACS Network232-EDAIA7215-74321RDI RDIENDIP 34-6 API I/FApplicationLayerFigure 2.5 MDT/MRC Interface 2.2.1 Layer 1 The “A“ interface at the physical layer (OSI 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 leve
43、ls defined in these specifications are recommended (i.e., ON = +3 volts or greater, OFF = -3 volts or more negative). Conformance to physical connector specifications of EIA/TIA-232-E are not required. Reference Appendix B for the connector specification. This signal subset comprises the following:
44、V.24 EIA/TIA-232-E Description Direction 102 AB Common Both 103 BA Transmitted Data (TD) DCE Input 104 BB Received Data (RD) DCE Output 107 CC Data Set Ready (DSR) DCE Output 133 CJ Ready for Receiving (RFR) DCE Input 106 DB Clear to Send (CTS) DCE Output The following additional signals are optiona
45、l: V.24 EIA/TIA-232-E Description Direction 108 CD Data Terminal Ready (DTR) DCE Input 113 DA Transmit Data Clock (TDC) DCE Input 115 DD Receive Data Clock (RDC) DCE Output The functionality of these signals is discussed briefly below. (On the “A“ interface, the DCE corresponds to the mobile gateway
46、.) TIA/EIA/TSB69.1-2 14 Common: This circuit establishes the common ground reference potential for all interchange circuits. CTS: Signals on this circuit are generated by the DCE to indicate whether or not the DCE is ready to transmit data or, in the case of a serial automatic dialing DCE, to accept
47、 dialing or control signals. This DCE output is used by the DCE to throttle the DTE. When ON, it indicates that the DTE may send data towards the DCE. When OFF, indicates that the DTE should not send data towards the DCE. Transmitted Data: Signals on this circuit are generated by the DTE and are tra
48、nsferred to the local DCE for transmission of data to remote DCE(s), or for maintenance or control of the local DCE. Received Data: Signals on this circuit are generated by the local DCE in response to data signals received from the remote DCE(s), or by the local DCE for maintenance or control purpo
49、ses. DSR: Signals on this circuit are used to indicate whether the DCE is ready to operate. As commonly implemented, this signal is hard-wired ON in the harness, and is not controllable by the software. RFR: Signals on this circuit control the transfer of data on Received Data circuit, indicating whether the DTE is capable of accepting data. This DCE input is used by the DTE to throttle the DCE. When ON, indicates that the DCE may send data towards the DTE. When OFF, indicates that the DCE should not send data towards the DTE (RFR has always been in V.24, but is a
