ANSI TIA EIA-136-620-A-2001 TDMA Third Generation Wireless - Teleservice Segmentation and Reassembly (TSAR).pdf

1、ANSI/TIA/EIA-136-620-A-2001 Approved: May 4, 2001 TIA/EIA STANDARD TDMA Third Generation Wireless - Teleservice Segmentation and Reassembly (TSAR) TIA/EIA- 136-620-A (Revision of TINEIA-136-620) MAY 2001 TELECOMMUNICATIONS INDUSTRY ASSOCIATION Tlie Telecoininiiiiicatioiis Industry Association repres

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9、TR-45.3 Subcommittee on Time Division Digital Technology.) Published by TELECOMMUNICATIONS INDUSTRY ASSOCIATION 2001 Standards and Technology Department 2500 Wilson Boulevard Arlingon, VA 22201 PRICE: Please refer to current Catalog of EIA ELECTRONIC INDUSTRIES ALLIANCE STANDARDS and ENGINEERING PUB

10、LICATIONS or call Global Engineering Documents, USA and Canada (1-800-854-7179) International (303-397-7956) All rights reserved Printed in U.S.A. TINEIA-I 36-620-A Contents 1 . Teleservice Segmentation and Reassembly . 1 2 . Procedures . 4 2.1 Mobile-Originated Segmented Message 4 2.2 Mobile-Termin

11、ated Segmented Message 5 2.3 Mobile-Terminated Segment Reassembly Time-out 6 2.4 Mobile-Originated Segment Interval Time-out 6 3 . Message Set . 8 3.1 TSAR Begin Message 8 3.2 TSAR Continue Message 9 3.3 TSAR End Message 10 3.4 TSAR Response Message 11 4 . Information Element Description 12 4.1 CRC1

12、 . 12 4.2 CRC2 . 12 4.3 CRC Status 13 4.4 Compression 13 4.5 Encryption . 13 4.6 Length of Acknowledgment Map 13 4.7 Segment Data 14 4.8 TSAR Acknowledgment Map . 14 4.9 TSAR Acknowledgment Window 14 4.10 TSAR Protocol Discriminator . 15 4.1 1 Teleservice Message Length . 15 4.12 TSAR Message Type .

13、 15 4.13 TSAR Optional Services . 16 4.14 TSAR Optional Services Support Map 16 4.15 TSAR Segment Data Length . 16 4.16 TSAR Sequence Number . 17 4.17 TSAR Status 17 4.18 TSAR Transaction ID 17 . 5 . Timer Values . 18 6 . Change History for TIA/EIA-136-620 19 I TIAIEIA- 1 36-620-A List of Figures Fi

14、gure 1 TSAR Protocol Stack 2 Figure 2 Teleservice Message Segmentation 2 II TINEIA-I 36-620-A I 1. Teleservice Segmentation and 2 Reassembly 8 9 10 II 12 13 14 15 16 17 18 Teleservice Segmentation and Reassembly (TSAR) provides a mechanism to deliver TIA/EIA-136 Teleservice Messages (e.g., as defiie

15、d in CMT or OATS) that are not constrained by any message length limitations imposed by the air interface or network layers supporting the teleservice. The service consists of the application of segmentation the acknowledgment of correct receipt of segments is either via the R-DATA Accept or an expl

16、icit TSAR Response message. When a message is segmented, each segment must be delivered in such a way that the original message can be reassembled. Each TSAR message includes a TSAR message header that contains a sequence number indicating the order in the original Teleservice message. Following thi

17、s TSAR message header is the segmented portion of the original application message. 1 TIAIEIA- 1 36-620-A Message Header 4 Message Data 9 Figure 1 depicts the relations between each of the services offered by the Segmentation and Reassembly function and the Teleservice and Air Interface. The Service

18、 Access Points (SAP) defining the boundaries of the TSAR Layer are identified. Finure 1 TSAR Protocol Stack I I 4 Teleservice Message Teleservices Dialog Teleservice Message The TeleseNice message is logically transferred directly to the far end peer TeleseNice The actual message deliveiy involves s

19、everal sewices Assembly Service TSAR Services are utilized to distribute the TeleseNice message into as many Air Interface 1 A The Air Interface provides the necessaiy message size limits necessaiy to insure Network Sewices constraints are not violated t L3 SAP Air Interface Service Network Service

20、b Air Interface Service Segmentation is performed such that the entire application-layer teleservice message is included in the segmentation, to avoid application-layer headers from having to be repeated for each segment. Figure 2 shows the application of segmentation to an arbitrary teleservice mes

21、sage: Figure 2 Teleservice Message Segmentation Original Teleservice Message * TSAR Message . *. TSAR Message Segmented Message 2 TINEIA-I 36-620-A I 2 3 4 5 6 7 8 9 10 II 12 13 14 15 16 17 18 19 20 21 The originator of the teleservice message, whether it be the BMI or the mobile station, performs t

22、he necessary segmentation of the message prior to transmission. For the BMI (mobile terminated R-DATA), the Calculation of R-DATA Message Length specified in TIA/EIA-136-910 may be used to identi the maximum message length that can be sent in one R-DATA; if the original teleservice message exceeds t

23、his length, then the BMI shall segment the message, with the segment size being less than or equal to the maximum message length specified in TIMEIA- 136-9 10. For the mobile station (mobile-originated R-DATA), the mobile station shall first check the R-DATA Message Length IE in the Access Parameter

24、s message (see TIA/EIA-136-123), then follow the information contained in TIMEIA-136-910 (Calculation of R-DATA Message Length), to identi the maximum message length. If the message length is greater than the specified R-DATA Message Length or exceeds the lengths specified in TIA/EIA-136-910, the mo

25、bile station shall segment the message, with the segment size being less than or equal to the maximum message length allowed. The TSAR Layer at the termination point of the teleservice message performs reassembly of the original teleservice message prior to delivering the message to the teleservice

26、application. The termination point may be either the BMI or the mobile station. For seamless integration with the existing Teleservice definitions in TIMEIA-136, the HLPI is partitioned into three fields (HLPI, see TIMEIA-136-700). If the Teleservice Segmentation and Reassembly Indicator of the HLPI

27、 is set, then the associated Teleservice message is segmented. 3 TIAIEIA- 1 36-620-A I 2 3 2. Procedures 4 2.1 5 6 7 8 9 10 II 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 The following Teleservice Segmentation and Reassembly Procedures apply to

28、message transactions on the DCCH and the DTC. Mobile-Originated Segmented Message When the mobile station is to originate a teleservice message, it shall perform the following: 1. The mobile station teleservice application delivers a complete message to the TSAR Layer. If the mobile station is on a

29、DCCH, the TSAR Layer checks the R-DATA Message Length obtained from the Access Parameters message on the F-BCCH (see TIA/EIA- 136- 123), and determines if the complete teleservice message length (plus R-DATA message overhead) exceeds the R-DATA Message Length. For delivery of R-DATA messages over th

30、e DTC FACCH or SACCH, the R-DATA Message Length parameter does not apply, and the information contained in TIMEIA-136-910 (Calculation of R-DATA Message Length) shall be followed. If the teleservice message length exceeds the allowable limit, (broadcast andor guidelines in TIA/EIA-136-910), then the

31、 TSAR Layer must segment the message into segments sized less than or equal to the allowable limit; note that each segment is contained in a TSAR message which contains a message header that must be accounted for. Each segment must end on an octet boundary, with padding as necessary on the last segm

32、ent. If the teleservice message does not exceed the allowable limit, then the TSAR Layer delivers the complete message to Layer 3 without change. The TSAR Layer assigns a TSAR transaction Id to this TSAR message stream. Based on the Teleservice application, the TSAR Layer identifies if optional serv

33、ices are to be supported (i.e., Compression, Encryption, and CRC Computation). The TSAR Layer, also depending on the application, identifies if and how often the receiving TSAR entity is to return receipt confirmation and populate the Acknowledgment Map information element. The TSAR Layer formats th

34、e first segment into a TSAR Begin message with a sequence number of zero, and includes header information and any information elements necessary to specifi the optional services. Intermediate segments are formatted into a TSAR Continue message, with a sequence number incremented by one for each segm

35、ent. The final segment is formatted into a TSAR End message. 2. 3. 4. 5. The TSAR Layer delivers the TSAR message to Layer 3, indicating in the Teleservice Segmentation and Reassembly Indicator in the HLPI that segmentation has been applied. Unless this is the last TSAR Message to be (re)sent and TS

36、AR Response is prohibited, the TSAR Layer starts the Segment Transmission Interval Timer (SEGINT-TMR), which is used to indicate the interval in which the next segment must be sent. If this is the last segment, the timer indicates the interval in which the TSAR Response is expected. The segment is s

37、ent on an R-DATA. Layer 3 receives an R-DATA ACCEPT, and delivers this acknowledgment to the TSAR Layer. 6. 7. 4 TINEIA-I 36-620-A I 2 3 4 5 6 7 8 9 10 II 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 8. The TSAR Layer delivers the remaining segments as per Steps 5 and 6, w

38、ith each segment sent within the time specified by SEGINT-TMR. Upon delivery of all segments, the TSAR Layer awaits the response(s) from the receiving TSAR entity if acknowledgments were requested, and notifies the teleservice application of the delivery result. 9. If the mobile station re-selects t

39、o a different DCCH during a segmented teleservice message delivery, and the R-DATA Message Length changes, then the mobile station shall resend segments beginning with the sequence number just before the segment resizing. 2.2 Mo b i I e-Te rm i na te d Seg men te d M es sage When a teleservice messa

40、ge is delivered to a mobile station, it shall perform the following: 1. 2. 3. 4. 5. 6. The mobile station Layer 3 receives an R-DATA. The Teleservice Segmentation and Reassembly Indicator indicates that Teleservice Segmentation has been applied, and the message containing this segment is delivered t

41、o the TSAR Layer for reassembly. The TSAR Layer checks the TSAR Message Header in the received message, identifies the transaction for which this segment applies (via the TSAR Transaction ID in the TSAR Message Header), and stops the Reassembly Timer (REASSEM-TMR) for this transaction. The TSAR Laye

42、r includes the Segment Data with any previously received segments for this transaction in order as determined by the TSAR Sequence Number. If the received message is a TSAR Begin Message, the TSAR Layer determines if any optional services are to be invoked for this message by checking the TSAR Optio

43、nal Services information element. During a point-to-point TSAR transaction, the TSAR Layer notifies Layer 3 that this portion of the message is acceptable, and if this is not the last segment, starts a Re-assembly Timer (REASSEM-TMR) for this transaction. If a TSAR Acknowledgment is required as a re

44、sult of receiving this segment, the TSAR Layer generates a TSAR Response Message and delivers it to Layer 3 for transmission. Layer 3 sends an R-DATA ACCEPT, unless the R-DATA message was received on the S-BCCH. Steps 1-4 are repeated for all segments. Upon receipt of all the segments, the TSAR Laye

45、r completes reassembly and any optional TSAR facilities employed and delivers the teleservice message to the teleservice application as identified by the HLPI. If a Acknowledgement is required upon receipt of all segments, the TSAR Layer formats a TSAR Response Message and sends it to the sending TS

46、AR entity. 5 I 2 3 4 5 6 7 8 9 10 II 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 TIAIEIA- 1 36-620-A 2.3 Mo bile-Termi nated Segment Reassembly Ti me-Out The following is the procedure for a mobile station handling of a Reassembly Timer expiration during a point-to-poi

47、nt TSAR transaction: The mobile station TSAR Layer has an open transaction (as identified by the TSAR Transaction Id) for reassembly of a segmented teleservice message. One or more segments have already been received for this transaction, and the Reassembly Timer (REASSEM-TMR) is running, indicating

48、 the TSAR Layer is waiting for an additional segment(s). The Reassembly Timer (REASSEM-TMR) expires, with no further segments received. If the TSAR Acknowledgment Window indicates that No TSAR Response is allowed, the TSAR Layer may notifj the teleservice application layer that a failed message atte

49、mpt has occurred (in the event the application has error handling), and discards the segment(s) already received for the transaction. The TSAR Layer closes the transaction. If the TSAR Acknowledgment Window indicates that TSAR Response is allowed, a TSAR Response Message shall be sent requesting retransmission of the failed segment (as indicated in the Acknowledgment Map) and containing a TSAR Status of Inter-Segment Timeout. If the TSAR Layer later receives an intermediate or final segment for the closed transaction, it notifies Layer 3 that the message is unacceptable. Lay