I’ve heard it said recently that there seems to be more industry interest to incorporate femtocells into the set-top box which sits alongside your TV than in the broadband DSL or cable modem. This seems a bit strange to me. What are the pros and cons of each approach?

Incorporating into the DSL modem

Prioritising the femtocell traffic (especially voice) above that of other data services in the home should reduce the risk of poor quality or dropouts during voice calls. Many of today’s DSL modems have integrated VoIP sockets allowing standard wired phones to be connected. These take priority over all other router ports to ensure improved call quality.

Many (most?) users may not notice any poor quality audio, which is most likely in homes that have intensive broadband data use, especially uploading. It may be more common where activities such as a large backup or substantial video file upload to YouTube is ongoing (or peer to peer file sharing).

The location of the modem may be a problem. If these are stuck away in a cupboard or closet far away from where the mobile phones are used in the home, then in some cases the signal strength may be affected. However, since most DSL modems nowadays also have Wi-Fi included, the femtocell would be expected to provide at least as good (and probably better) radio link to devices so this shouldn’t be a problem.

Incorporating into the TV Set top box

Located in the main living room, the set top box provides an ideal location from an RF perspective. The very short distance means little risk to the quality of the signal. Several applications which integrate operation of the set top box and the femtocell have been demonstrated, for example to display Caller ID on the TV when someone calls your mobile phone.

Vendors such as Pirelli Broadband Systems have demonstrated working models of this concept at trade shows for some time.

Integrated into the home control systems

A third possibility is to integrate the femtocell with the household control systems. Applications which can be provided by the femtocell include features such as turning on and off electrical appliances in the home, for example turning the lights on/off when the first/last person enters/leaves the building. These and other applications can use standard interfaces/architectures such as DNLA. An application of this type was demonstrated by ip.access with their partner AlertMe earlier this year.

Where direct wired connections are required, perhaps this might be better if located near the modem but if using powerline or wireless for remote control then I doubt if this would matter.

Summary

I’ve been surprised to hear the growing interest for integrating femtocells with the set top box rather than the DSL modem, and frankly somewhat surprised not to have seen a commercially launched DSL modem/femtocell yet. My own view is that the priority for voice traffic enabled when the femtocell is integrated with the DSL or Cable modem makes it a logical choice.

If you have any insights or suggestions as to why that might be the case, feel free to comment below. (You can do so anonymously if you prefer).