Bill Pechey looks at recent advances in the Digital European Cordless Telecommunications standard and wonders what the effect will be on wireless markets
Much has been said about IEEE 802.11b wireless LANs and Bluetooth recently, but far less about another wireless technology Digital European Cordless Telecommunications (Dect). Many of you will already know that Dect is a technology used for cordless phones, but you might not know that it has a lot more to offer in terms of wireless networking.
Over the years, Dect has quietly developed into a complete wireless telecommunications system with a wide range of data capabilities. The voice capabilities are enhanced for use with PBXs and include roaming between access points 'fixed parts' in Dect parlance.
Dect may also be used to provide Wireless Local Loop (WLL) services and ranges of up to 17 kilometres are possible with special antennae. This capability is reflected in the fact that the International Telecommunication Union (ITU) has accepted Dect as one of the five technologies for accessing 3G networks. However, the work on data capabilities is driving Dect into the areas where 802.11b and Bluetooth are strong.
For example, Dect Packet Radio Service (DPRS) is similar to GPRS but provides higher speeds up to 1Mbit/s and lower delays. In the past few days, the European Telecommunications Standards Institute (ETSI) has announced the initiation of a project to increase the data rates provided by Dect to about 20Mbit/s. When this work is done, Dect will have the ability to compete with 802.11b and Bluetooth in all areas.
Let's take a look at the problem areas of Bluetooth and 802.11b, and see how Dect measures up. The 802.11b standard has suffered from criticisms of the strength of its security systems. Dect uses a scheme very similar to that used by GSM, which has never been seriously compromised. Bluetooth has no workable mechanism at present for hand-over between access points. Dect has had a tried and tested scheme for many years.
Many people are worried about interference in the 2.4GHz band that is shared between 802.11b, Bluetooth, microwave ovens and many other systems. Dect operates at 1.9GHz, in a band allocated solely for its use. The only interference is from other Dect systems and Dect has the ability to swap channels to avoid such interference, although there could still be problems in areas of high traffic.
While it is one thing for a standard to have the right capabilities, it is quite another to make that standard a success in the market. The semiconductor industry has a lot of experience with making low-cost low-power Dect chips and many of the current Bluetooth designs can be traced back to technology developed for Dect. As a consequence, technology problems are unlikely to be a barrier to success.
There are now hundreds of companies working on Bluetooth designs and, perhaps, dozens working on 802.11b. This represents a considerable momentum and those companies are not likely to change direction. The traditional Dect manufacturers may seize the opportunity to compete by taking advantage of Dect's strong points and there could well be some confusion.
In the end, I expect that Dect, Bluetooth and 802.11b will find their own riches but there are bound to be areas of overlap. How large these areas become remains to be seen.