IP: the true reality of GRPS speeds & latency

[David Farber <dave () farber net>]

> From: "the terminal of Geoff Goodfellow" <geoff () iconia com>
> To: "Dave E-mail Pamphleteer Farber" <farber () cis upenn edu>
>
>
> Brown's GPRS trials -- speeds and why GPRS may not work properly for data
>
> M2 Presswire via Factiva 2001-11-23 (13:37:25)
>
> Brown's, mobile data developers in Blackheath, London, have conducted
> extensive tests with the new GPRS networks. The company has identified
> several issues to be addressed before the service will be suitable for
> widespread use by corporates in mobile computing applications. (It was
> reported in the Financial Times, 21st November 2001 that Orange in the UK
> has delayed the launch of its network partly because it is concerned about
> the quality of handsets and applications).
>
> Brown's tests show that the speed of GPRS in the outbound direction, at
> least on lightly-loaded networks, is an impressive 4k bytes per second and
> that the latency (delay on the round trip) is comparable to that of a
> circuit-switched data connection.
>
> But, whilst GPRS is supposed to be an always-on connection, it is no more
> reliable than GSM and realising "always-on" is challenging. Just like any
> other mobile connection, there are occasions when the link drops, leaving
> the user high and dry, and interrupting file downloads and so on.
>
> Brown's Managing Director, Geoff Brown says:
>
> "Experience shows that if you are working on a train, with your laptop
> online and you enter a tunnel, for example, you will often lose your IP
> connection. With GPRS, when you reconnect, you may well be given another IP
> address and have to re-authenticate to the server and start again.
>
> Also, if you lose the GPRS context, there is no way that the centre can go
> out and remake that connection. It can only rely upon the remote end
> re-trying the link to re-establish the context. Corporate users will need
> remote mobile software that will rebuild the connection automatically and
> seamlessly when conditions are right."
>
> Users should bear in mind that, as yet, there are no roaming agreements in
> place for GPRS. This means that a data user can take advantage of GPRS in
> the UK but will need to switch to an alternative network or buy a local SIM
> card to work overseas. Even when roaming agreements are in place, the
> systems as offered by the operators will not provide end-to-end security so
> sensitive data could be exposed on inter-network links.
>
> Brown's trials were done with BT Cellnet in the UK, D2 Vodafone in Germany
> and Telstra in Australia. In the UK, neither Orange nor One2One are offering
> a GPRS service so far. Vodafone and BT Cellnet are concentrating on offering
> it to big companies via private lines but the actual take-up could be
> limited by some of the shortcomings that Brown's has identified.
>
> Brown's concludes that purpose-built client software for PC or PDA will be
> essential before corporates can make practical use of GPRS.
>
> --SNIP--
>
> http://www.wirelessroadmap.com/news&analysis_2001/Brown_GPRS_trials113001.ht
> m
>
> =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
> geoff.goodfellow () iconia com, Prague CZ * tel/mobil +420 (0)603 706 558
> "success is getting what you want & happiness is wanting what you get"
> http://www.nytimes.com/library/tech/99/01/biztech/articles/17drop.html

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