Subject: [NEXTEL-1] What's wrong with this story?

From: [email-masked]
Date: Fri, 15 Aug 2003 10:47:23 -0400

What's wrong with this story?
<SNIP>
Nextel pioneered the PTT (Direct Connect) service in 1996, based on Qualcomm’s
QChat software technology and integrated by Motorola into its iDEN (Integrated
Dispatch Enhanced Network) network. It uses the 800MHz portion of the radio
spectrum assigned to specialized mobile radio (SMR) service. The iDEN network uses
both half-duplex and full-duplex signals. A normal cell phone call uses two
separate frequencies, one to send and one to receive, but PTT requires only a
half-duplex signal, saving bandwidth and making the initial connection much
faster. (The server can instantly detect if it is a dispatch call).
It has been reported that Qualcomm gave Nextel exclusive rights to use Qchat in
the US with the anticipated result that Nextel will migrate to CDMA2000 when the
timing is right. Because of this, no other operator was able to offer Qchat in the
past, allowing Nextel to build up a subscriber base of over 11 million users.
=====================================================================================

Wireless operators race to offer ‘push-to-talk’
Chinmei Sung, DigiTimes.com, Taipei [Friday 15 August 2003]

The news about Verizon Wireless, the largest mobile operator in the US, to roll
out push-to-talk (PTT) services on August 18 is perhaps one of the biggest buzzes
in the telecom industry in recent weeks. Not only does Verizon’s decision to foray
into the PTT market pose a threat to Nextel Communications, the nation’s
fifth-largest wireless carrier and the sole PTT service provider in the world, but
the action also seems to endorse the notion that PTT is the next big thing in the
mobile telecom industry.

According to a recent report by the Economist, Nextel’s ARPU (average revenues per
user) is US$67, compared to the nation’s average US$54, and its churn rate is
1.7%, compared to the nation’s average of 2.4%.

Nextel pioneered the PTT (Direct Connect) service in 1996, based on Qualcomm’s
QChat software technology and integrated by Motorola into its iDEN (Integrated
Dispatch Enhanced Network) network. It uses the 800MHz portion of the radio
spectrum assigned to specialized mobile radio (SMR) service. The iDEN network uses
both half-duplex and full-duplex signals. A normal cell phone call uses two
separate frequencies, one to send and one to receive, but PTT requires only a
half-duplex signal, saving bandwidth and making the initial connection much
faster. (The server can instantly detect if it is a dispatch call).
It has been reported that Qualcomm gave Nextel exclusive rights to use Qchat in
the US with the anticipated result that Nextel will migrate to CDMA2000 when the
timing is right. Because of this, no other operator was able to offer Qchat in the
past, allowing Nextel to build up a subscriber base of over 11 million users.

Recently, a consortium of major handset vendors including Nokia, Ericsson and
Siemens set about to define a new standard for push-to-talk based on IMS (IP
Multimedia Subsystem). IMS is an IP standard defined by the 3G Partnership Project
(3GPP). One important capability of IMS is that it has the ability to find a
person via SIP to initiate a session.
Since it is a Voice over IP (VoIP) service, a handset needs to have an IP address
to send packets. Since GPRS networks dynamically allocate IP addresses from the
base stations, it must somehow keep track of the IP address during the total
connection (even during handoffs to new cell areas). This is one of the reasons
why there is a major problem with latency.
Some call this type of software-based PTT “Voice Instant Messaging,” meaning not
true PTT since there is a delay in the communication. There may be ways to improve
this service and make it compete somewhat with Nextel’s Direct Connect, perhaps by
giving higher paying users priority service to the PTT servers.

Handsets with a special PTT button do not seem to be a big issue. Since this
method is software-based, it may be just as simple to buy an additional hands-free
kit with PTT button, instead of having to buy a new phone.
Although Motorola has marketing rights for Qchat Direct Connect product outside of
the US, it decided to purchase another push-to-talk company called Winphoria
Networks, whose soft switch technology is also based on IMS. Winphoria is rumored
to be the application vendor of choice for Verizon.

Nextel’s not standing still, however. In a move to safeguard its market position
in advance of the new competition, the company last month registered the
trademarks “PTT” and “Push-to-Talk.” The carrier also plans to launch nationwide
PTT service in August in addition to upgrading its service to work with other CDMA
networks.

http://www.digitimes.com/NewsShow/Article.asp?datePublish=2003/08/15&pages=PR&seq=204

------------------------ Yahoo! Groups Sponsor ---------------------~-->
Buy Ink Cartridges or Refill Kits for Your HP, Epson, Canon or Lexmark
Printer at Myinks.com. Free s/h on orders $50 or more to the US & Canada. http://www.c1tracking.com/l.asp?cid=5511
http://us.click.yahoo.com/l.m7sD/LIdGAA/qnsNAA/61FxlB/TM
---------------------------------------------------------------------~->

Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/

---

From: "Paul Holliday" <[email-masked]>
Date: Fri, 15 Aug 2003 10:52:07 -0400

Nexhell PTT requires only a half-signal! (NOT)
----- Original Message -----
From: <[email-masked]>
To: <[email-masked]>
Sent: Friday, August 15, 2003 10:47 AM
Subject: [NEXTEL-1] What's wrong with this story?

> Nextel pioneered the PTT (Direct Connect) service in 1996, based on
Qualcomm's
> past, allowing Nextel to build up a subscriber base of over 11 million
users.
============================================================================
=========
>
> Wireless operators race to offer 'push-to-talk'
> in the telecom industry in recent weeks. Not only does Verizon's decision
to foray
> into the PTT market pose a threat to Nextel Communications, the nation's
> According to a recent report by the Economist, Nextel's ARPU (average
revenues per
> user) is US$67, compared to the nation's average US$54, and its churn rate
is
> 1.7%, compared to the nation's average of 2.4%.
>
> Nextel pioneered the PTT (Direct Connect) service in 1996, based on
Qualcomm's
> Some call this type of software-based PTT "Voice Instant Messaging,"
meaning not
> this service and make it compete somewhat with Nextel's Direct Connect,
perhaps by
> Nextel's not standing still, however. In a move to safeguard its market
position
> trademarks "PTT" and "Push-to-Talk." The carrier also plans to launch
nationwide
> PTT service in August in addition to upgrading its service to work with
other CDMA
http://www.digitimes.com/NewsShow/Article.asp?datePublish=2003/08/15&pages=P
R&seq=204

---

From: [email-masked]
Date: Fri, 15 Aug 2003 11:01:10 -0400

It gets better........ "Nextel pioneered the PTT (Direct Connect) service in 1996, based on Qualcomm's QChat software
technology" (NOT)

Q-Chat was not even invented in 1996!

Anybody see any other Boo-Boo's?

--
    "NEXTEL-1 IT'S NOT JUST NEXTEL"
  Note The New address
Subscribe to Nextel-1: http://www.groups.yahoo.com/subscribe/NEXTEL-1

  "NEXTEL2 FOR iDEN SOFTWARE DEVELOPERS"
Subscribe to Nextel2: http://www.groups.yahoo.com/subscribe/NEXTEL2

  "WIRELESS FORUM HOMELAND SECURITY GROUP"
     The Complete Resource for Wireless Homeland Security.
Subscribe to WFHSG:  http://www.groups.yahoo.com/subscribe/WFHSG

---

From: Rick Parrish <[email-masked]>
Date: Fri, 15 Aug 2003 20:28:52 -0500

[email-masked] wrote:

>The iDEN network uses both half-duplex and full-duplex signals. 
>
That's not too far off the mark - iDEN uses 6 slot TDMA. Dispatch needs 
one slot, a phone conversation requires two time slots.

>A normal cell phone call uses two separate frequencies, one to send and one to receive, but PTT requires only a half-duplex signal, saving bandwidth and making the initial connection much faster.
>
That was true for AMPS which is largely irrelevant (sorry Alan Dixon). 
The writer blows it here by saying "frequencies" instead of something 
more abstract like "channel" or "connection" to mean a time slot without 
having to go through the pain of explaining TDMA. Also, the half-duplex 
data doesn't move any faster.

>(The server can instantly detect if it is a dispatch call).
>It has been reported that Qualcomm gave Nextel exclusive rights to use Qchat in the US with the anticipated result that Nextel will migrate to CDMA2000 when the timing is right. 
>
Who or what was the source of this "QChat" association with Qualcomm?

There *was* some noise about Nextel migrating away from iDEN, but I 
don't think they've committed to any specify technology such as 
CDMA2000. Who'd want to finance this one?

>Because of this, no other operator was able to offer Qchat in the past, allowing Nextel to build up a subscriber base of over 11 million users.
>
Again, where did this line of BS come from? Anyone confirm the 11 
million figure?

>Nextel pioneered the PTT (Direct Connect) service in 1996, based on Qualcomm’s QChat software technology and integrated by Motorola into its iDEN (Integrated Dispatch Enhanced Network) network. 
>
Either Nextel or Motola owns "Direct Connect" as a trade or service 
mark. Either way, this does not make Nextel a "pioneer" of PTT. What 
does SoLink call their PTT service? Nextel bought up SMRs - which were 
existing 2-way dispatch push-to-talk services; most of which predated 
Nextel, iDEN and even MIRS.

>It uses the 800MHz portion of the radio spectrum assigned to specialized mobile radio (SMR) service. 
>
Look! A factual statement.

>Recently, a consortium of major handset vendors including Nokia, Ericsson and Siemens set about to define a new standard for push-to-talk based on IMS (IP Multimedia Subsystem). IMS is an IP standard defined by the 3G Partnership Project (3GPP). One important capability of IMS is that it has the ability to find a person via SIP to initiate a session.
>
FYI: SIP is a directory service ... conceptually like DNS.

>Since it is a Voice over IP (VoIP) service, a handset needs to have an IP address to send packets. Since GPRS networks dynamically allocate IP addresses from the base stations, it must somehow keep track of the IP address during the total connection (even during handoffs to new cell areas). This is one of the reasons why there is a major problem with latency.
>
Okay, pretty good statement so far ...

>Some call this type of software-based PTT “Voice Instant Messaging,” meaning not true PTT since there is a delay in the communication. 
>
This statement is pure fluff. All packetized voice - particularly voice 
data that has been compressed - has a delay. The label "software-based 
PTT" fails to distinguish one carrier's PTT service from another since 
all digital telephony requires software. Latency times on Nextel (as 
described on this list a few months back) are awful. The first 
astronauts on the moon had better latency back to earth (okay, I 
exagerate)! I'd like to see ALL carriers improve latency times on normal 
phone voice calls as well as "simplex voice".

>There may be ways to improve this service and make it compete somewhat with Nextel’s Direct Connect, perhaps by giving higher paying users priority service to the PTT servers.
>
There's two kinds of latency - (a) the delay from when something is 
spoken until it can be heard at the other end and (b) the delay from 
pressing the button until the handset actually receives permission from 
the cell tower/controller to begin transmitting. A priority scheme 
imlies pre-empting existing conversations when a particular switch or 
controller is near capacity - that's a great way to piss-off customers.

>Handsets with a special PTT button do not seem to be a big issue. Since this method is software-based, it may be just as simple to buy an additional hands-free kit with PTT button, instead of having to buy a new phone.
>
Depends upon how hard it would be to upgrade the handset's firmware.

>Although Motorola has marketing rights for Qchat Direct Connect product outside of the US, 
>
Is this true? You'd think that Motorola was smart enough to invent their 
own.

>In a move to safeguard its market position in advance of the new competition, the company last month registered the trademarks “PTT” and “Push-to-Talk.” 
>
We've already beaten that one to death!

>The carrier also plans to launch nationwide PTT service in August in addition to upgrading its service to work with other CDMA networks.
>  
>
-rick