Subject: [NEXTEL-1] Mis-Conceptions about Nextel's Push-To-Talk used in public safety applications.

From: [email-masked]
Date: Mon, 24 May 2004 10:39:06 -0400

Mis-Conceptions about Nextel's Push-To-Talk used in public safety
applications.

There should be a disclaimer concerning Push-To-Talk systems used in
public safety applications.

Using Nextel as a "Back-up" or "Secondary" communication device has its
problems as one poster here has pointed out
( http://www.apco911.org/theexchange/index.cgi?read=2769) Communications
on the Nextel / iDEN network are typically not recorded (But can be with
right interface). There is no-way to "Override" a transmission in case
of emergency as in a "conventional" (non-trunked) system. As many
dispatchers know and do in an emergency.

There are many misconceptions when it comes to the use of Push-To-Talk.
Many of these misconceptions are repeated by our trusted public safety
officials because they believe what they have been told by wireless
carriers. Some of them are:
1) PTT- Uses a "Private Network" and is not susceptible to failure from
outside carriers because all traffic is carried with its own network.

1A) This is simply not true as I said before outside carriers provide
the transport and are susceptible to failure. If any one would like to
see incidents when an outside carrier caused a failure of PTT I will be
glad to provide it.

2) PTT- Worked Flawlessly in 9/11

2A) PTT- Worked marginally. Again if anyone is interested in messages
from those who were there I would be glad to share them.

3) Nextel/iDEN is "a true 800 MHz radio system"

3A) Nextel/ iDEN is not "a true 800 MHz radio system" as some may think.
It is a ESMR network that uses cellular type architecture to provide
PTT. The only thing that remotely resembles a "true 800 MHz radio
system" are the SMR frequencies that it operates on. It is a Packet
based digital network that uses a TDMA M-16 QAM air interface.
Read More Here:
http://idenphones.motorola.com/idenHome/common/what_is_iden.jsp

4) Nextel/ iDEN is a tool for Public Safety.

4A) Nextel / iDEN is tool for BUSINESS only.

Nextel and some other iDEN carriers have implied that this is a public
safety tool. If you read Motorola's description below you will see there
is NO mention of public safety.

The iDEN Solution
First introduced in 1994, Motorola's Integrated Digital Enhanced Network
(iDEN™) brought to the
market next generation wireless solutions designed for a variety of
vertical market mobile business
applications. Today, iDEN wireless handsets are utilized in a variety of
work environments ranging
from manufacturing floors to executive conference rooms as well as
mobile sales forces.

Read it for yourself.....

http://idenphones.motorola.com/idenHome/common/what_is_iden.jsp
Nextel / iDEN has its place, but using a device for which it is not
intended for has it consequences.

5) Nextel's Direct Connect works on a separate radio network.

5A) Nextel's interconnect and Direct Connect all travel across the same
airwaves (within the same
17 Khz of bandwidth). It all goes across the same T1 back to the switch.
The only separation is at
the Dispatch Application Processor (DAP at the switch). The Dispatch
Application Processor
coordinates and controls the Direct Connect dispatch service

- Processes Private, Group, and Alert Calls

- Contains subscriber data on individual fleet and unit information,
dispatch and ID features, subscriber talkgroup information, and a unit's
calling privileges. The DAP still requires other resources that are
shared with the "Interconnect" (cellular) feature.

6)Nextel / iDEN easily implemented means of communicating with these
other agencies within their
existing budgets,

6A)Cost of owner ship is not cheap. The Lifetime Revenue Per Wireless
Subscriber for Nextel is $4,303 as of 2Q03 (for consumers and X 2.5
$10,757.5) for P/S.

http://ocw.mit.edu/NR/rdonlyres/Sloan-School-of-Management/15-020Fall2003/47239EEB-7BB2-4AFD-9834-75E29637DD2B/0/lec10_nextel.pdf

For a small department consisting of 100 officers this represents a OPEX
(Operating expense) of over$1 Million dollars and the department has no
additional assets to show. $1 million can buy a lot of solutions to
provide interoperability.
There are many more "myths" about Nextel/iDEN that have been circulated
for many years and many people believe what wireless carriers tell them.

I say to everyone - Do your own due diligence, just don't regurgitate
what your wireless carrier tells you. This goes for all carriers just
not Nextel, because the liability will fall on YOUR department not
Nextel if something should happen.
BTW- Everyone should read Nextel's Liability disclaimer-

LIMITATION OF LIABILITY - Nextel nor any of its affiliates, nor the
directors, employees or other representatives of any of them, is liable
for damages arising out of or in connection in any way with the use of
or inability to use the Site, Materials, products, services or
applications. This is a comprehensive limitation of liability that
applies to all damages of any kind, including but not limited to,
compensatory, direct, indirect or consequential damages, loss of data,
programs, income or profit, loss of or damage to property and claims of
third parties.

Coverage-

Coverage boundaries, shown herein as of Aug 2003 are approximate and for
illustrative purposes only. Coverage shown on the coverage maps is a
general prediction of outdoor coverage, and does not guarantee that
coverage will be available at all covered geographic areas at all times.
Wireless coverage is impacted by, among other things, terrain, weather,
antenna location, system modification, foliage and man-made structures
(such as buildings), and therefore cannot be predicted precisely at all
times. Nextel's Nationwide Network serves 293 of the top 300 markets.

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