DECT

DECT = Digital Enhanced Cordless Telephony. Probably the most evolved system for medium range (cell diameter ca. 50m) wireless telephony. Very common in Europe.

What is DECT?

• DECTweb Article – What is DECT?
• Techworld Article – DECT vs Wifi and Bluetooth

DECT – VOIP Products

• CAT-iq (“Cordless Advanced Technology-internet and quality”)
• Ascom IP-DECT Base Stations and IP-DECT Gateways for the combination of legacy and IP-DECT in the same system, http://www.ascom.com/en.
• KIRK IP DECT, new systems 6000 and 8000 are “made” for Asterisk, flexible Application Interface, new handset series 50xx, 60xx and 70xx, colour display and preconfigured Icons, see German Webpage COMPLUS General distribution KIRK DECT.
• Snom M3 a DECT SIP phone with colour display.
• Siemens Gigaset C450IP S675IP S685IP a DECT dual mode SIP/PSTN low-cost unit. Connects to VoIP directly via Ethernet for PC-less operation.
• Polycom (Kirk) – SIP, Skinny and H323 capable DECT gateways. Products are sold as OEM by innovaphone and tiptel.
• http://www.nec-ipdect.com More about NEC – great in combination with Asterisk. DECT/GAP roaming,…
• http://www.rtx.hk RTX handsets – great combination with Asterisk system or any other SIP complaints. Skype, single/multi site SIP dect phones
• http://dect.osmocom.org Open Source (GPL) software DECT stack for Linux, includes asterisk channel plugin

How to integrate DECT with Asterisk.

For small scale applications, you should consider the Siemens Gigaset C470IP. For about 60 Euro you get a handset and a VoIP enabled Basestation. You can add up to 5 additional handsets (e.g. the Gigaset 67h, 55 Euro). The Gigaset van work with 6 SIP accounts and an additional landline. Unfortunately, it can only handle two simultaneous SIP calls. With additional repeaters (ca. 100 Euro reach) you probably can get coverage for a 100x100m office building. Using the Gigaset C470 IP is probably the cheapest way at the moment to get VoIP Handsets to a group of people. You end up at 60 Euro per Phone with no additional cabling or switch port cost.

If you have to cover a larger area or need more Handsets you need something more enterprise. The most important feature is probably “roaming” and “handover”. When a handset leaves the radio coverage of a base station end enters the coverage of the next station the call must be transparently moved from one base station to the other.

The Aastra-Detewe RFP 32 IP-DECT-Basestation, the Ascom IP-DECT System, the Polycom KIRK IP 600V3 SIP Wireless DECT Server Base and the NEC Philips AP200 address that market and all work with Asterisk. Polycom KIRK DECT systems can use multiple base stations (cells) and repeaters to achieve large coverage areas and high user density 1500 users+. The Polycom KIRK Server 300 targets the small office market, supporting up to 12 handsets and 6 repeaters. New Polycom KIRK DECT systems for the Asterisk market Polycom Kirk KWS6000 and Polycom Kirk KWS8000.

Aastra and NEC Philips are more geared to the “professional solution provider” which means it is extremely hard to get documentation, firmware, license keys and the like. The Base stations are configured via DHCP options and need to load their firmware via TFTP at each reboot (only one time needed for NEC Philips). There is no documented API to remotely configure the devices, NEC Philips is configurable with dedicated (Windows) software.

The Ascom and Polycom KIRK devices are more suited for “the network guy” and documentation etc. are more readily available. They come with APIs for configuration. Note that the Ascom system claims to support 100.000 users in one single system. Polycom KIRK base units (600v2 & 300) include a web-based provisioning GUI but can also support centralized provisioning.
The Polycom KIRK 6000 and 8000 servers with SIP interface are easy to integrate and cheaper than the 600v3 systems.

It is noteworthy that the Aastra and Polycom KIRK systems can be used not only with the (expensive) DECT handsets from Aastra and Kirk but also with all DECT/GAP handsets. Siemens Gigaset Handsets (e.g. the Gigaset 67h, 55 Euro) are mostly made for the consumer market, are low price/adequate quality products and are very familiar to the users because most of the user have one at home. Be careful: all the features as “transfer” are not available with all DECT handsets! Only Polycom KIRK 4020 and 4040 are really industrial handsets and can survive in very hard environments.
The KIRK 6020 is the new handset for the industrial environment, the KIRK 6040 is equipped with life-saving detectors. Note an application is necessary.
The KIRK 7010 and 7020 are build for healthcare systems, the 7040 as well.

The open source DECT stack available at http://dect.osmocom.org supports single-cell systems with up to 10 transceivers, resulting in a maximum capacity of 60 concurrent calls. Multi-cell support is being worked on.

News

• 2004-11-23 RTX Provides DECT Cordless Phones for Net-Based Calls BizReport Story

See Also:

• DECTweb – DECT news, product directory, general information
• DECT Forum – DECT Industry Association