Question about Nextel 800MHz enterference

Archived from groups: alt.cellular.nextel (More info?)

On Fri, 31 Dec 2004 23:04:09 -0700, "Rich" <nomore@spam.no> wrote:

>I just posted this to alt.cellular and then found this group.. which I think
>this message belongs in..... please see my question below:
>
>I just bought a couple i710 phones with Nextel and whenever the phone is on
>I hear a clicking sound in my computer speakers and my monitor goes
>completely wild (horizontal lines) when I am speaking with someone on the
>i710.
>
>I used to have a Cricket phone and never had a problem with this around
>speakers or computer monitors.
>
>Cricket works at 1900Mhz while Nextel works at 800Mhz. I suppose this has
>something to do with the static I'm hearing/seeing.
>
>Here is my question. I don't know a lot about this... or how this works, but
>is the Nextel phone outputting more hazardous radiation if I am able to see
>the static in the monitor and hear the static in my speakers?
>
>I just plunked out a lot of money for these phones and had absolutely no
>idea they caused interference like this. I hope I am not exposing myself to
>more radiation than I had with my old cell phone.

The clicking is the phone transmitting to the tower. Nextel is famous
for this.

As to radiation.... Wear a tin foil hat.
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Archived from groups: alt.cellular.nextel (More info?)

Nextel uses iDEN, which is also based on the same principals as GSM and TDMA .
Meaning that they use a TIME based digital modulation scheme. NON continuous TX...

What you are hearing is the TX (transmitter) pulsing as it just transmits during it's time slot.
So, it's not the frequency the phone is operating at, it's the (TDMA) digital scheme it's using.

Your Cricket uses CDMA, which is a spread spectrum transmission, less likely to
cause RFI (radio frequency interference) in close proximity devices.

One could speculate that there is the possibility that at 1900MHz, the pulsing TX of an
iDEN or other TDMA based device would cause less RFI because of the shorter wavelengths.
ERP being the same.



"Rich" <nomore@spam.no> wrote in message news:g1rBd.3783$232.2335@fed1read05...
>I just posted this to alt.cellular and then found this group.. which I think
> this message belongs in..... please see my question below:
>
> I just bought a couple i710 phones with Nextel and whenever the phone is on
> I hear a clicking sound in my computer speakers and my monitor goes
> completely wild (horizontal lines) when I am speaking with someone on the
> i710.
>
> I used to have a Cricket phone and never had a problem with this around
> speakers or computer monitors.
>
> Cricket works at 1900Mhz while Nextel works at 800Mhz. I suppose this has
> something to do with the static I'm hearing/seeing.
>
> Here is my question. I don't know a lot about this... or how this works, but
> is the Nextel phone outputting more hazardous radiation if I am able to see
> the static in the monitor and hear the static in my speakers?
>
> I just plunked out a lot of money for these phones and had absolutely no
> idea they caused interference like this. I hope I am not exposing myself to
> more radiation than I had with my old cell phone.
>
>

Archived from groups: alt.cellular.nextel (More info?)

Steve Sobol wrote:
> *Rich wrote:
>
> > Someone in another group suggested it is GSM vs CDMA.. does one
> emit more
> > radiation than the other??
>
> Nextel is neither GSM nor CDMA. iDEN is a hybrid two-way/cellular
> protocol
> based on TDMA. (GSM is also based on TDMA, but isn't the same
> protocol.)
>
> --
> JustThe.net Internet & New Media Services, http://JustThe.net/
> Steven J. Sobol, Geek In Charge / 888.480.4NET (4638) /
> sjsobol@JustThe.net
> PGP Key available from your friendly local key server (0xE3AE35ED)
> Apple Valley, California Nothing scares me anymore. I have three
> kids. *

KE4QPF writes:

Courtesy - http://tinyurl.com/429t5

TDMA (Time Division Multiple Access):
iDEN's digital technology divides a channel into different "slots".
Each slot can carry one voice or data transmission. By deploying an
iDEN system, service providers can increase capacity by as much as six
times their current analog Specialized Mobile Radio (SMR) network.

This capacity increase is accomplished using a state-of-the-art
technology called TDMA. TDMA utilizes Global Positioning Satellites
(GPS) to reference a synchronized time, and then divides the channel
into time slots. As a result, channel capacity is increased because one
channel has now been converted to multiple voice or data transmission
vehicles. TDMA is a proven technology in cellular systems across
Europe, the US, and in Japan. iDEN utilizes TDMA for Maximum Spectrum
Efficiency.

VSELP (Vector Sum Excited Linear Prediction):
VSELP digitally codes and significantly compresses voice signals,
increasing radio channel capacity by reducing the amount of information
that needs to be transmitted. VSELP provides iDEN systems with the
capability to fit voice transmission into the smaller transmissions
vehicle that results from TDMA.

QAM (Quad Amplitude Modulation):
Quad Amplitude Modulation results in 64 kbps data rate over a 25 kHz
channel.


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