Short-Message Service Functions in C#.NET

Scan Denso QR Bar Code in C#.NET Short-Message Service Functions

13:

Figure 1313 MS-based SME message origination under call handoff conditions: (1) MS-based SME-A sends an air-interface message, SMD-REQ, to the serving system (2) The call has previously been handed off from the anchor system to a tandem system and then to the current serving system; therefore, the serving system routes the short message towards the anchor system using the SMSDeliveryBackward Invoke (SMDBACK) message (3) The tandem system forwards the SMDBACK message to the anchor system (4) The anchor system then sends the message to SME-A s MC, using the SMDPP message Acknowledgment messages are relayed forward through the handoff chain to SME-A

As we see in Table 133, routing proceeds per our first example in Table 132 until step 3 At this point, SME-A s MC must send the SMDPP message to SME-B s MC Since SME-B is identified with an IP address, SME-A s MC sends the SMDPP message via a TCP/IP network, where it terminates on SME-B s MC Noting that the message is intended for IP-B, and that IP-B is currently associated with MS-B, SME-B s MC sends the SMDPP message to MS-B s current serving system (eg, via an SS7 transport network using the SMS_Address provided by the serving system) SME-B s MC informs the serving system that the origi-

Downloaded from Digital Engineering Library @ McGraw-Hill (wwwdigitalengineeringlibrarycom) Copyright 2004 The McGraw-Hill Companies All rights reserved Any use is subject to the Terms of Use as given at the website

Part 2:

Figure 1314 MS-based SME message termination under call handoff conditions: (1) A message destined for MS-based SME-A is sent by SME-A s MC to the anchor system (2) The call has previously been handed off from the anchor system to a tandem system and then to the current serving system; therefore, the anchor system routes the short message towards the serving system using the SMSDeliveryForward Invoke (SMDFWD) message (3) The tandem system forwards the SMDFWD message to the serving system (4) The serving system sends the air-interface message, SMDREQ, to SME-A Acknowledgment messages are relayed back through the handoff chain to the MC

nal destination address is IP-B, while the intermediate destination address is MIN-B (the MIN associated with MS-B) The serving system should, at this point, send the message to MS-B, identifying the destination address as IP-B A Final Word on Short-message Addressing and Routing Unfortunately, while they are flexible, the ANSI-41 short-message addressing and routing mechanisms are also complex and subject to interpretation The fact that ANSI-41 refers to idealized air-interface

Downloaded from Digital Engineering Library @ McGraw-Hill (wwwdigitalengineeringlibrarycom) Copyright 2004 The McGraw-Hill Companies All rights reserved Any use is subject to the Terms of Use as given at the website

13:

Figure 1315 Another basic message origination and termination sequence, involving different network technologies: (1) MS-based SME-A sends an air interface message, SMD-REQ, to the serving system (2) The serving system routes the short message to SME-A s MC, using the ANSI-41 SMDPP message The SMDPP message is routed by using the same SS7 signaling network as is used for routing other ANSI-41 messages When the smdpp message is received from the MC, the serving system converts it into an air-interface acknowledgment, the SMD-ACK message (3) SME-A s MC may apply an originating supplementary service to the short message (this is not currently defined in ANSI-41); the SMDPP message is then routed to the destination SME s MC by using a TCP/IP network (4) SME-B s MC may apply a terminating supplementary service to the short message (this is not currently defined in ANSI-41); the SMDPP message is then routed to the destination SME s serving system by using the SS7 signaling network (5) The serving system forwards the short message toward the destination SME using the air-interface SMD_REQ message SME-B responds with an automatic acknowledgment (SMD-ACK) to signal acceptance of the SMD-REQ message

messages (eg, the SMD-REQ message) rather than real air-interface messages makes things that much more difficult to decipher TR453, the subcommittee with responsibility for the TDMA air-interface standards, has attempted to limit the potential for confusion by pro-

Downloaded from Digital Engineering Library @ McGraw-Hill (wwwdigitalengineeringlibrarycom) Copyright 2004 The McGraw-Hill Companies All rights reserved Any use is subject to the Terms of Use as given at the website