[Asterisk-Users] Wireless phones connected to VOIP DECT basestation

[dean collins]

As one of the people who introduced both DECT and CT3 into the
Australian enterprise market I'll take a crack at answering this. If
anyone thinks this information is worthwhile I'll add it to the Wiki.

DECT is a cordless phone solution. It can be sold as a stand alone
single handset - single base station residential solution however it's
main use is in a multiple base station multiple handset corporate
solution.

It is an evolution of the original proprietary CT3 technology developed
by Ericsson in 1993. It was released as an open standard in 1996 and
although some technical changes were made to CT3 to become DECT it is
more or less the same.

It is a TDMA style transmission with between 8-12 time slots per base
station (vendor dependant). Generally each base station is powered
locally and cabled back to a central point in a star configuration.

You can generally get between 200 to 400 meters from the handset to the
base station, though with the use of external yagi antennas you can get
good directional connectivity for up to 1000m.

Dect allows seamless handover and roaming between base stations, and
although not widely published there are mobility location servers that
allow you to use the same handset at multiple locations.
Eg. I could be an area supervisor using my handset at one Home Depot and
I travel to the next Home Depot and the mobility server will recognize
that you are; 
A- at the new location  
B- tell the pabx to divert all of your calls to the new site.

Whilst originally sold as a stand alone adjunct box to a pabx (generally
using an E1 connection between the pabx and the DECT adjunct box) it has
over the past 6 years evolved to where most PABX (European anyway) can
connect the base stations directly to a chassis card installed directly
in the PABX backplane.

In 1998 the G.A.P. (Generic Access Profile) standard was published that
allowed most handsets to operate with most base stations however it is
generally a subset of the full proprietary feature list. (also known by
the vendors as Go Away Please).

There were a number of dual mode gsm/dect handsets developed over the
years (I myself used to use a dual mode CT3/GSM Ericsson handset in 96
and later occasionally a Dual mode GSM/Dect Nokia handset) however they
were not widely available and had a number of issues, generally battery
life because most of them generally ran two internal radios
simultaneously.

There was of course no roaming between the dect and gsm carrier
networks.

One of the reasons you may not be familiar with DECT is that it was
mainly a European standard (also NEC had a solution called PHS that was
only ever available in Japan). 

Motorola and Lucent (or the Avaya division today) had a competing less
capable solution called CT2 (less features, less time slots per base,
less density per given area and also less roaming between bases
stations).

CT2 was also trialed as a poor mans cellular in Canada, 2 state based
USA trials, and Hong Kong.

Basically it allowed one way calling (eg handset to base only) so you
could make outgoing calls but not receive calls.

The Hong Kong solution was probably the most successful of these of
these and interestingly they also had a built in pager for receiving
text messages.

There are no public access CT2 solutions currently operating.

There are a number of interesting parallels to draw between the CT2 and
DECT rollouts and the current Wifi Voip handsets........and let me tell
you if you think there is nothing to learn from history then well you
must know it all.

Will WIFI Voip handsets replace desk based cabled handsets?
Do end users really need combined VOIP/GSM handsets?
Will carriers ever introduce mobility between enterprise VOIP and GSM?
Where can enterprises benefit from a mobile solution?
How can a carrier benefit from the changing technology to offer higher
value add solutions in the enterprise market.
Will voip wifi offer the ability for a small and nimble voip carrier to
compete against the mobile gsm carriers.
Which manufacturers are leading development and how do I find them.

These and many other points are available to be learned by anyone who
wants to talk to me about them. I'm now based in NY and can be reached
via this email address.


Cheers,
Dean







-----Original Message-----
From: asterisk-users-bounces at lists.digium.com
[mailto:asterisk-users-bounces at lists.digium.com] On Behalf Of Michael
Graves
Sent: Saturday, October 30, 2004 11:25 AM
To: Asterisk Users Mailing List - Non-Commercial Discussion
Subject: Re: [Asterisk-Users] Wireless phones connected to VOIP DECT
basestation

On Sat, 30 Oct 2004 09:37:00 +0200 (CEST), Remco Barende wrote:

>Hi list!
>
>I found an interesting wireless phone product. Tiptel will be selling a

>base station for DECT phones that is VOIP capable. The base station
comes 
>in two models, one with the SCCP the other with H.323 protocol support.
>
>The interesting bit is that the base station is VOIP connected but you
can 
>use standard (cheap) DECT phones to connect to it.
>
>I found it on www.tiptel.nl (the websites in other countries do not 
>mention this model) and the model is called tiptel DECT-Z 600 IP
systeem
>
>Yu can find it on www.tiptel.nl -> producten -> DECT Draadloze 
>telefoonsystemen -> tiptel DECT-Z 600 IP systeem
>http://www.tiptel.nl/fr_top.asp?lang_id=1&mid=901&pid=901
>
>Unfortunately the product page is in Dutch only.
>
>I wonder if Tiptel make this themselves or whether they bough an OEM 
>product from a manufacturer. When googling I could not find a similar 
>product though and there aren't nay mentioned under Wireless VOIP in
the 
>wiki either.
>
>Are there other similar base stations?

Please forgive my ignorance, but what exactly is DECT? I don't see the
term referenced anywhere in North America.

Michael


--
Michael Graves                           mgraves at pixelpower.com
Sr. Product Specialist                          www.pixelpower.com
Pixel Power Inc.                                 mgraves at mstvp.com

o713-861-4005
o800-905-6412
c713-201-1262

!michael.tag



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