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1、 TIA DOCUMENT Project 25 Common Air Interface Description for Conventional Channels TIA-102.BAAD DECEMBER 2003 TELECOMMUNICATIONS INDUSTRY ASSOCIATION The Telecommunications Industry Association represents the communications sector of Copyright Telecommunications Industry Association Provided by IHS
2、 under license with EIALicensee=IHS Employees/1111111001, User=Wing, Bernie Not for Resale, 03/29/2007 21:07:17 MDTNo reproduction or networking permitted without license from IHS -,-,- NOTICE TIA Engineering Standards and Publications are designed to serve the public interest through eliminating mi
3、sunderstandings between manufacturers and purchasers, facilitating interchangeability and improvement of products, and assisting the purchaser in selecting and obtaining with minimum delay the proper product for their particular need. The existence of such Publications shall not in any respect precl
4、ude any member or non-member of TIA from manufacturing or selling products not conforming to such Publications. Neither shall the existence of such Documents preclude their voluntary use by non-TIA members, either domestically or internationally. TIA DOCUMENTS TIA Documents contain information deeme
5、d to be of technical value to the industry, and are published at the request of the originating Committee without necessarily following the rigorous public review and resolution of comments which is a procedural part of the development of a American National Standard (ANS). Further details of the de
6、velopment process are available in the TIA Engineering Manual, located at http:/www.tiaonline.org/standards/sfg/engineering_manual.cfm TIA Documents shall be reviewed on a five year cycle by the formulating Committee and a decision made on whether to reaffirm, revise, withdraw, or proceed to develop
7、 an American National Standard on this subject. Suggestions for revision should be directed to: Standards then go on to step 6. 5. Complete Retry. Send a NACK with Class = %01, Type = %001, Status = N(S), and with no flags (i.e. blocks_to_follow = 0), according to the Common Air Interface; and conti
8、nue on to step 6. 6. Wait for a Transmission. Wait for the sender to transmit another copy of the packet. The receiver may wait indefinitely in this state. Once another transmission is received proceed with step 7. 7. Test the Retransmission. At this point the receiver has to distinguish three diffe
9、rent cases. Case 1. FMF=1. In this case a new First Copy packet has been received. The receiver should start over with step 1 and then go to step 2. This can occur if the last retransmission of a packet fails to be received, and the originator starts over with a new packet. Case 2. FMF=0 and N(S)n.
10、In this case a retransmission of a different packet has been received. The receiver may ignore the transmission and return to step 6 to wait some more. Case 3. FMF=0 and N(S)=n. In this case an expected retransmission has been received. The receiver proceeds to step 8. 8. Save blocks passing the CRC
11、-9 parity check. For each block in the packet, if the CRC-9 passes, then update the buffered packet block according to the serial number in the block and mark the block as received so that selective retries will not be requested. If not all of the blocks have passed the CRC-9 parity check, then go b
12、ack to step 4. Otherwise proceed to step 9. 9. Test the Packet CRC. Now the 32-bit packet CRC is tested. If this parity check fails, then the receiver requests a complete retransmission by going to step 5. If the parity check passes then finish up in step 10. Copyright Telecommunications Industry As
13、sociation Provided by IHS under license with EIALicensee=IHS Employees/1111111001, User=Wing, Bernie Not for Resale, 03/29/2007 21:07:17 MDTNo reproduction or networking permitted without license from IHS -,-,- TIA 102.BAAD 28 10. Process the Packet and Send an Acknowledgment. At this point the pack
14、et has passed all the CRC checks. Send an ACK with Class = %00, Type = %001, and Status = N(S). Test the packet sequence number, N(S), against V(R). If N(S) = V(R) and the packet CRC = last_packet_CRC, then the packet is a duplicate and should be discarded. Otherwise the packet is accepted and the r
15、eceiver shall send it to the Service Access Point (SAP) indicated in the header block. If an encrypted service is selected, then the packet will be decrypted at this point. Set V(R) N(S), and last_packet_CRC CRC of this packet. Copyright Telecommunications Industry Association Provided by IHS under
16、license with EIALicensee=IHS Employees/1111111001, User=Wing, Bernie Not for Resale, 03/29/2007 21:07:17 MDTNo reproduction or networking permitted without license from IHS -,-,- Copyright Telecommunications Industry Association Provided by IHS under license with EIALicensee=IHS Employees/1111111001
17、, User=Wing, Bernie Not for Resale, 03/29/2007 21:07:17 MDTNo reproduction or networking permitted without license from IHS -,-,- Copyright Telecommunications Industry Association Provided by IHS under license with EIALicensee=IHS Employees/1111111001, User=Wing, Bernie Not for Resale, 03/29/2007 21:07:17 MDTNo reproduction or networking permitted without license from IHS -,-,-