Disclaimer: These archives are mirrored from smsforum.net in 2007 before the forum got closed. Please only part of the forum is available here.
For any clarifications regarding these archives you can contact us at http://www.telecomspace.com/contact.

      TELECOMSPACE HOME PAGE         TELECOM DISCUSSION FORUM          CONTACT

+  SMS Forum Online Discussion
|-+  SMS Technologies
| |-+  ANSI-41 (CDMA & TDMA) Related (Moderator: SMS Forum Support)
| | |-+  CDMA SMS Clarifications
« previous next »
Pages: [1] Go Down Print
Author Topic: CDMA SMS Clarifications  (Read 751 times)
nagesh.kumar
Full Member
***
Offline Offline

Posts: 28


« on: December 20, 2006, 05:21:43 UTC »

Hi Experts,

I have taken a look all the old mail threads and there is real useful information that is presented on how  SMS works in CDMA. (Many thanks for that.) However, there are couple of points which I could not gather from the threads conclusively. I would request you to kindly clarify the same.

1. In the thread SMSC to SMSC (http://smsforum.net/smf/index.php?topic=2472.0 ) and as per CDMA SMS call-flows, it was mentioned that the SMS sent by the originator is sent to Orignator's MC (SMSC) when there are SMS supplementary services for User A. (Else the SMS can be sent the receiver's MC (SMSC)). Is this how the SMS routing done in normal CDMA deployments? In other words, does the SMS reach the originator's SMSC in CDMA deployments?

2. In the same thread SMSC to SMSC (http://smsforum.net/smf/index.php?topic=2472.0 ), while discussing deliver report acknowledgement, it was mentioned "that it is not clear how common SMSC-SMSC legs are via ANSI-41 and In many cases, something like SMPP can be used instead". As a part of other threads it was mentioned in CDMA networks, SMSC-SMSC communication is via SMPP. Which is the most widely
deployed mechanism?

If SMPP is used, my understanding is that we can't really deliver a Delivery Report from destination SMSC to originating SMSC? Is this understanding right?

This problem will NOT be there in GSM networks, since originating SMSC will directly deliver the SMS to the destination user.

3. Also in the standards that are referenced in the thread (http://smsforum.net/smf/index.php?topic=2472.0), the call-flows 7.6 and 7.7. show that the protocol between MC (SMSC) and a Fixed-SME is done using SMDPP message? Again - is it ANSI-SMDPP message or SMPP, that is typically used in CDMA deployments to communicate between SMSC and Fixed-SME/ESME?

I appreciate your help in clarifying the same. Thanks to all once again.

Regards
Nagesh
Logged
SMS Forum Support
SMS Forum Support
Administrator
Sr. Member
*****
Offline Offline

Posts: 1754


WWW
« Reply #1 on: December 20, 2006, 22:15:38 UTC »

Quote
I have taken a look all the old mail threads and there is real useful information that is presented on how  SMS works in CDMA. (Many thanks for that.) However, there are couple of points which I could not gather from the threads conclusively. I would request you to kindly clarify the same.

Its possible technically at standard level.. but not always the case. The US rarely uses SMSC-SMSC SS7 handover for ANSI.. reason being that its not always possible to know that both phones are the same technology (CDMA->CDMA, TDMA->TDMA).

Quote
1. In the thread SMSC to SMSC (http://smsforum.net/smf/index.php?topic=2472.0 ) and as per CDMA SMS call-flows, it was mentioned that the SMS sent by the originator is sent to Orignator's MC (SMSC) when there are SMS supplementary services for User A. (Else the SMS can be sent the receiver's MC (SMSC)). Is this how the SMS routing done in normal CDMA deployments? In other words, does the SMS reach the originator's SMSC in CDMA deployments?

I don't believe it has to reach the SMSC.. if the CDMA environment has IMSI support, then technically as SS7 level, network A can terminate into network B.. which would result inonly one SMSC being used; specifically that of the sender.

But because of the unknowns in posting across networks and technologies, its simply the case that the messages often get routed off-SMSC through inter-carriers, with portability dips performed and finally get routed to the dest network, where it may again route to one of several different technology SMSCs, depending on what kind of phone the subscriber has... in that case, it always ends up on the destination SMSC or at least some part of the destination network.

Quote
2. In the same thread SMSC to SMSC (http://smsforum.net/smf/index.php?topic=2472.0 ), while discussing deliver report acknowledgment, it was mentioned "that it is not clear how common SMSC-SMSC legs are via ANSI-41 and In many cases, something like SMPP can be used instead". As a part of other threads it was mentioned in CDMA networks, SMSC-SMSC communication is via SMPP. Which is the most widely
deployed mechanism?

In pure GSM, its all done using SS7.. it works brilliantly.. long live GSM. But because ANSI technologies got the raw deal with lack of IMSIs and lagged behind GSM, they have been forced to co-deploy.. this is the case across US & Asia.. as a result, SMPP has been the shiny hammer to solve the routing and allow for generic inter-network messaging while providing some level of abstraction from the underlying technologies.

Quote
If SMPP is used, my understanding is that we can't really deliver a Delivery Report from destination SMSC to originating SMSC? Is this understanding right?

For a standard SMSC receipt, yes that is correct.

This problem will NOT be there in GSM networks, since originating SMSC will directly deliver the SMS to the destination user.

Quote
Also in the standards that are referenced in the thread (http://smsforum.net/smf/index.php?topic=2472.0), the call-flows 7.6 and 7.7. show that the protocol between MC (SMSC) and a Fixed-SME is done using SMDPP message? Again - is it ANSI-SMDPP message or SMPP, that is typically used in CDMA deployments to communicate between SMSC and Fixed-SME/ESME?

No thats Short Message Delivery Point to Point.. its an ANSI term akin to forward short message in GSM.. is a MAP structure defined in ANSI MAP for carrying MO or MT messages.
Logged

Regards,
   Cormac Long
   Webmaster & Technical Enquiry Moderator,
   SMS Forum

nagesh.kumar
Full Member
***
Offline Offline

Posts: 28


« Reply #2 on: December 21, 2006, 13:44:30 UTC »

Hi Cormac,

Thanks yet again for your clarifications.


Quote

I don't believe it has to reach the SMSC.. if the CDMA environment has IMSI support, then technically as SS7 level, network A can terminate into network B.. which would result inonly one SMSC being used; specifically that of the sender.

But because of the unknowns in posting across networks and technologies, its simply the case that the messages often get routed off-SMSC through inter-carriers, with portability dips performed and finally get routed to the dest network, where it may again route to one of several different technology SMSCs, depending on what kind of phone the subscriber has... in that case, it always ends up on the destination SMSC or at least some part of the destination network.



I understood your clarification regarding the routing in CDMA domain if IMSI were to be there. It would be the same as that of GSM. And, if IMSI support is NOT there, the SMSC of sender would deliver it to SMSC of recipient via SMPP. This is fine.

Does the SMS get routed to Home-SMSC of the sender, when the sender is roaming (assuming IMSI support is NOT there) - like in GSM? (All the call-flows in the CDMA standard show the call-flow when the receipient is roaming - I didn't find one where the sender is roaming.)

Quote
No thats Short Message Delivery Point to Point.. its an ANSI term akin to forward short message in GSM.. is a MAP structure defined in ANSI MAP for carrying MO or MT messages.

My clarification is - whether ANSI MAP is used between SMSC and Fixed SME in CDMA or is it SMPP? In GSM, the standard 23.039 explicitly mentions that SMPP as one of the candidates for interface between SMSC and ESME. However, I didn't find a similar standard in CDMA. On the contrary CDMA mentions ANSI-MAP as the interface between  SMSC and Fixed SME. I would like to know whether it is ANSI-MAP or SMPP that is typically used between SMSC and Fixed SME in CDMA?

Thanks once again for your help in clarifying the same.

Regards
Nagesh
Logged
shad
Sr. Member
****
Online Online

Posts: 54


« Reply #3 on: December 22, 2006, 16:54:29 UTC »

Hi Nagesh

Re 1, the most common (and recommended) approach is for "indirect routing", i.e. to send the message from the sender's serving MSC to the sender's home SMSC. This allows a billing record to be produced in the home network for the message (helpful since most CDMA MSCs don't produce billing records for SMS), and also relieves the serving MSC of the need to understand the roamer's SMS dialplan, e.g. short codes, which intercarrier agreements are in place etc. The MSC just needs to route based on the sender's identity, and doesn't have to examine the Destination Address.

Re 2, others on the board know more about SMPP, but the protocol does define a Delivery Receipt. It seems possible to me for a mobile to originate an SMS with Delivery Acknowledgment requested, and have their SMSC request a delivery receipt on the subsequent inter-SMSC SMPP leg. When the message is successfully delivered in the destination network, the SMPP delivery receipt is sent and the sender's SMSC could turn that back into an SMS Delivery Acknowledgment Message. Still, I don't think that it is common for this to work. It may be that the presence of brokers like mobile365 in the middle make this economically unviable, as they would charge for the receipt message just like any other SMS.

Re 3, I think SMPP (or other IP-based protocols) is much more common than ANSI-41 for ESME interfaces, due to the cost of SS7 links. Perhaps there would be exceptions in certain implementations of network nodes like OTAF or Voicemail...

Smiley
Shad
Logged
nagesh.kumar
Full Member
***
Offline Offline

Posts: 28


« Reply #4 on: January 02, 2007, 05:37:52 UTC »

Hi Shad,

Thanks for the clarifications.

I am also not sure about second point. Probably other experts can comment on it.

Regards
Nagesh
Logged
Pages: [1] Go Up Print 
« previous next »
Jump to:  


Login with username, password and session length