IMS Applications We Could See In the Near Future

IMS, the IP Multimedia Subsystem, a buzzword that has been around in the mobile industry for quite a number of years now. However, up to date no IMS services are commercially available and the industry is still working on getting the complex setup and terminal software in place.  In the past year, however, a number of things have happened which might improve chances we are going to see some interesting commercial services soon:

  • 3GPP Release 6 integrates WLAN access in IMS. Previously, IMS was only specified for 3G access.With WLAN integration dual mode 3G/Wifi devices that are now available on the market can be used for IMS services while camped in a wireless lan.
  • The IMS has become the carrier SIP environment of choice for both fixed line and wireless IP networks. Especially wireless operators with DSL access will be able to offer integrated fixed and wireless services. This is also referred to as Fixed Mobile Convergence.

And here are the services which I see coming (soon?):

  • Instant Messaging (IM): This is an easy service to implement from a network point of view as there are no special bandwidth and latency requirements. IM however is already done today via proprietary IM clients from Microsoft, Yahoo and others. Thus, I think IM via IMS will have a difficult time unless operators find a way to include Microsoft, Yahoo and other customers, have international connectivity in mind and offer interesting pricing for the service.
  • Push to Talk over Cellular (PoC): Another service that has been with us for quite a number of years now. One US operator had and still has an interesting PoC service but it is based on proprietary hardware/software which hurts general usage. There have been proprietary approaches to bring PoC to the GSM/UMTS world as well but none have really gained great traction due to pricing, user unfriendly clients on mobile phones and non interoperability between national and international mobile networks. IM can change this as the OMA PoC specification now allows vendors for the first time to offer standardized and interworking PoC Servers. This enables talk groups which span multiple national and international wireless networks. A standardized PoC solution will also bring better PoC clients on handsets and will increase the number of PoC capable handsets.
  • Addition of video during a voice call: Today, circuit switched 3G wireless networks a capable of transporting voice and video calls. In many cases, however, users would like to add a video stream to an ongoing voice call rather to start a video call in the first place. IMS offers a nice way of doing that by either adding video to an ongoing IMS voice call or to add a video session to an ongoing circuit switched call which is not controlled by the IMS. The later scenario is probably the one going to hit the market first as I thing circuit switched voice calls will be the dominant way voice calls are transported over the network for qutie some time to come. The transmission of the video can also be stopped at any time during the call to continue the conversation in voice only mode.
  • Voice Call Continuity (VCC): Standardized in 3GPP TS 23.206 this new IMS service offers quite a number of new possibilities for voice calls: Ongoing calls can be switched from Wireless to Wifi at any time using 2G/3G/Wifi handsets such as the Nokia N-series and E-series phones. Also, a call can be transfered at any time to another handset. Quite nice when you come home and would like to continue the call via the fixed line table phone with good hands-free/loudspeaker facilities. VCC requires a special client in the mobile again but since it is standardized it’s possible that many vendors will likely implement this. Imagine a combined VCC + addition of video during call scenario. You talk to somebody over the 3G network while you drive in the car, carry the phone with you into your apartment and then you transfer the call to your home entertainment system to activate a video feed for the rest of the conversation. Here’s a video from the Daidalos project which impressively demonstrates the possibilities.

In 2006, HSDPA was an important topic during the 3GSMWorldCongress in Barcelona. Let’s see, maybe IMS will be the topic of the year in 2007 during the conference. It would be nice to see real demos of some of the applications above.