IMS and FTTH, Smart Access Solution
FTTH + IMS (IP Multimedia Subsystem) application overview
Everyone wants more, both telecom operators and consumers.
IMS will be able to do all this!
IMS (IP Multimedia Subsystem) is the direction of core network evolution. With further development of core network, all existing users will gradually migrate to IMS, meanwhile, the development of optical fiber and phase-out of copper is bound to induce the demand of FTTH access to IMS.
Feasibility analysis of FTTH access to IMS
Though IMS originated from the 3GPP mobile multimedia services, after TISPAN taking IMS as fixed network evolution solution and studying deeper, it’s found that IMS architecture and network element design is much suitable for a large number of small scale gateway(for example, sip GW).
- Resolve problems appeared in FTTH that based on soft-switch SIP protocol, such as longer time-delay, lack of complementary operational capacity, etc.
- Operators take FTTH as the “information superhighway” to carry voice, data, video and other broadband service.
- Distributional IMS process ability. IMS distributional architecture not only improve network robustness, but also good to design higher capacity and performance network element.
- IMS supports sophisticated registered caching mechanisms. IMS bulk caching mechanism supports a large number of dynamic IP addresses access. After completing IMS registration, DNS assigned IP+UDP address cached in P-CSCF through service route headers, contact address, path headers.
- IMS provides stronger security for FTTH networks (including authentication). IMS support flow control function, in addition, its SIP protocol has great improvement compared to the softswitch.
- IMS platform provides more powerful processing performance. New type of core network, like IMS’s elements based on the high level of hardware platform, like multi-core CPU processing, its process performance is 10 times compare to softswitch.
In summary, compared to softswitch, IMS is more suitable for large scale FTTH access network application mode.
Smart Access solution and business
The key issues in FTTH multimedia services access to IMS
(1) Architecture of FTTH access to IMS
Being IMS user access layer equipment, FTTH, along with the CSCF, MMTel AS, complete the provision of multimedia services through registered IMS networks, TR069 management system manage and issue the data such as user accounts, passwords, logical ID and SIP Server domain name, its network infrastructure as shown in Figure 1.
(2) FTTH registration mechanism in IMS
The process of FTTH terminals registered in IMS is similar with that of common IMS user registration, but there are multiple independent users in multiports FTTH, so FTTH need to send registered request to IMS for these users separately.
For IMS core networks, multiple-user registration information and contact addresses are recognized from the same device in the same FTTH, so it can use IMS implicit registration mechanism to meet this requirement.
(3) FTTH service in IMS
There is no need special requirements on FTTH terminal for basic service and smart service, it’s ok to support IMS SIP protocol only. But there is special requirements on FTTH terminals for some supplementary services. For example, the hooking/functional button event (eg. Call Waitting) cannot be notified to IMS.