DECT may not seem sexy compared with 3G mobile phones or voice on Wi-Fi, but don’t ignore it. It's practical, it's well established, and it's moving into the Internet age.

DECT stands for Digital Enhanced Cordless Telecommunications, and was created by the European ETSI standard maker in 1988. It's very widely used in domestic phones, with about 200 million sold worldwide. Business DECT phones are available that connect into a PBX, but these aren't seen as exciting and aren't seen so commonly.

DECT details

The DECT standards makers got things right, defining a wireless standard that didn't waste batteries, but allowed good quality voice and sensible features such as allowing multiple handsets on one base station, sharing a phone socket. These handsets can page each other, act as an intercom, transfer calls amongst themselves, or conference.

The phones have a range of around 100m, which beats systems based on Wi-Fi or Bluetooth, and are very robust against interference form other traffic such as Wi-Fi.

With that basis, phone makers added in other features like a phone book - which can be called in from a mobile SIM card.

Technically, DECT uses the G.726 audio codec 32 kbit/s, on the 1880-1900 MHz band in Europe, and the 1920-1930MHz band in the US. It has ten or five carriers in Europe or the US, and uses an average transmission power of 10 mW in Europe - it can use 250mW but pm average it only uses one of the 24 possible time slots at a time to transmit.

To increase the interoperability and the features on offer, the DECT industry defined the GAP profile, which allows any GAP phone to register an any GAP based station. It's safe to assume that any consumer DECT phone supports GAP.

Into the future

With voice on Wi-Fi being promoted heavily, it would be tempting to look at DECT as a thing of the past, but there are several signs of robust life. For one thing, there's a growing trend for Internet gateway vendors to build a base station into their products we recently noted AVM, Zyxel and Siemens taking this approach. BT also supports DECT in its HomeHub domestic gateway.

Since these gateways already include a Wi-Fi base station that could support voice on Wi-Fi handsets, the act of building DECT into them is a strong vote of no-confidence in voice on Wi-Fi.

These devices do have a fairly fast turnover, and it may be that their vendors are using DECT as a stop-gap till VoFi phones crack the battery life problem, or till dual-mode phones become widespread. Or it may just be that DECT does exactly that people want, and is very cheap to build into these devices as an extra feature.

Further on - CAT-iq

The DECT community isn't going to take second place without a fight though. It has defined a new standard, CAT-iq, for the VoIP generation, announced late in 2006.

CAT-iq (Cordless Advanced Technology - internet and quality) is intended to use DECT's good radio performance and bring better quality sound and include Internet access. CAT-iq phones should be able to connect to Internet services such as stock quotes, phone books, IM and other things.

The DECT Forum claims that gateway vendors are adding CAT-iq base stations to their products, to support multipl-play services. So perhaps the gateway vendors have their eye on a CAT-iq future.

The first CAT-iq phones should appear during 2007, with more advanced ones - the ones that access the Internet = appearing through to 2009.

The DECT Forum will be hoping to follow up its success in branding DECT phones. Base stations will carry a CAT-iq logo to show they comply with the standard.

Will it fly?

Overall, while the level of excitement around CAT-iq is about what you'd expect for an upgrade to the bog-standard home phone, it has a lot of potential - precisely because it aims to replace the bog-standard home phone. Engadget has reported the first CAT-iq phone, a business-oriented device shown at CeBit by Binatone.

No-one has yet said anything about dual-mode CAT-iq, possibly because the DECT community has failed already with dual-mode DECT/GSM phones, which surfaced in Britain as BT's "OnePhone" in the late 1990s - a product less successful than its current Wi-Fi/GSM descendant, Fusion.

An old article on OnePhone gives a strange sense of déjà vu. The service was launched in 1999, after 18 months delay due to a lack of credible dual-mode handsets. Within a couple of years, it sank without trace.

Despite this, I wouldn't be surprised to see dual-mode CAT-iq/GSM phones creep into the market sometime in the next couple of years. If their Wi-Fi cousins don't get better quickly, they might even have a chance of succeeding.