The IMS technology has been promoted extensively the last few years, but few successful deployments have been shown. Although its introduction is slow, there are a large number of drivers that will eventually push converged services into the marketplace. What are the major drivers for IMS?
Some of the central drivers for innovation based on IMS are:
- Access Convergence â€“ The same device may be using different access technologies, some fixed and some mobile, to offer a similar service to the user. For example, a mobile phone may be able to connect both to the cellular network and a Wi-Fi network attached to a broadband network to make and receive phone calls. Text messages and instant messages could similarly be used in different access modes. IMS creates a common layer that the service and client can use to connect with different access networks.
- Device divergence â€“ The same service may be offered on multiple devices. Currently you receive voice calls and SMS only on your mobile phone, but you could also receive the same voice calls and SMS while on a PC. IMS facilitates offering the same service on multiple devices.
- Fixed mobile convergence is a combination of several of these drivers, but normally describes a single phone number that can reach either the mobile phone or the fixed phone at home. IMS is seen as a key enabler to reach FMC, although other technologies could also be used.
- Multi-play â€“ This is a broad term incorporating triple-play, quadruple play etc. which seeks to combine broadband internet, fixed telephony, TV and mobile telephony. Multi-play may not be a direct driver for IMS, but the services that multi-play providers wish to offer can often use IMS as part of the technology and are therefore drivers for IMS. The usage of IMS for telephony and texting within such a service is an obvious move, but IMS could also be used to combine media services such as audio and video streaming into the same user interface.
- Reduce costs for investment and operations â€“ The cost of the network infrastructure is often mentioned as a major driver for IMS. This seems to be a more long term driver than a short term driver, as early IMS deployments will be expensive but the price will drop drastically as the technology matures. This driver is probably more important for new carriers than those that already have existing infrastructure that is already paid for.
- Service convergence â€“ There are concepts that consist of combination of different services. An example would be two people talking or texting on the phone while watching the same TV broadcast on their mobile. The screen would show the TV broadcast, but would also allow the two people (or a whole group of people) to exchange text messages during the broadcast. There are a huge number of services that could consist of a combination of content/media, texting and voice services. IMS promises a common service layer for the client to access multiple services, facilitating common services within a single client.
- Service switching â€“ as a dialog changes, it is often useful also to change the means of communication. An example would be a switch from an instant messaging conversation to a voice call. IMS can help make this switching more seamless.
All of the frequently mentioned IMS drivers can be implemented by using other technologies. SIP and SIMPLE can be deployed outside the IMS framework. To some extent IMS adds an additional level of complexity to the solutions and many service providers will choose not to use IMS, but base their services on less complex and cheaper solutions. The main reason for using IMS compared to other technologies is the focus that will be placed on IMS interoperability testing.
Instant Messaging is often mentioned as a main driver for IMS. Like with other drivers, Instant Messaging can be and is deployed using other technologies. It is not a single service that is an IMS driver. It is the ecosystem of several services working together that will drive IMS type environments. It is the melting together of messaging on PC and Mobile, including SMS, MMS and more dialogue based interactive messaging, that shows the benefits of IMS. The benefits will only be visible gradually. The service providers who choose to move on IMS based services early will suffer from having to mature the technology, while service providers who choose to wait will suffer because those who moved early will have more flexibility to shape tomorrows services.