1993-02-05 - Re: `Sunday Times’ article on GSM changes

Header Data

From: Brad Huntting <huntting@glarp.com>
To: Jay Prime Positive <jpp@markv.com>
Message Hash: 0dcccb216bae9c4a1e86dbddc9292591a6004c9ed4db93df2fb7f29926b2e889
Message ID: <199302050147.AA14360@misc.glarp.com>
Reply To: <9302041407.aa14565@hermix.markv.com>
UTC Datetime: 1993-02-05 01:48:18 UTC
Raw Date: Thu, 4 Feb 93 17:48:18 PST

Raw message

From: Brad Huntting <huntting@glarp.com>
Date: Thu, 4 Feb 93 17:48:18 PST
To: Jay Prime Positive <jpp@markv.com>
Subject: Re: `Sunday Times' article on GSM changes
In-Reply-To: <9302041407.aa14565@hermix.markv.com>
Message-ID: <199302050147.AA14360@misc.glarp.com>
MIME-Version: 1.0
Content-Type: text/plain



> Speculation: The "A5 `scrambling code'" is used as the spreading code
> for a spread spectrum radio.

It would seem that both the sender and reciever need to be exactly
syncronized to within 1/4 of a bit for this to work.  Since voice
data requires about 64Khz, if you spread this by a factor of 32
(for a scrambling frequency of 2.048Mhz) this would mean the sender
and reciever would need to be synced to well within 500ns of each
other.

Isn't this a bit difficult?  How do they do it?


brad





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