[UA] [OT] Noddy version of how a mobile call finds the mobile phone

[Myles Corcoran]

Ysidro asked:
> While we're on the topic of cellphones, how does an incoming call to a
> cellular phone get routed to it?  Does the phone periodically check in
> with nearby stations to let the system know where it is?  Inquiring
> minds want to know.

	There are two databases that store the location and 
other info about a mobile. The Home Location Register (HLR) keeps 
all the permanent data and subscription details. It stores the 
address of the last Vistor Location Register (VLR) which is the 
temporary database for mobiles visiting a particular area (groups 
of groups of cells). You dial a mobile's number and the request 
is routed to the HLR, which requests in turn an address from the 
VLR. The VLR address is sent back to the original requesting 
switch which routes directly (more or less) to the VLR where 
the mobile is currently registered. There the VLR asks the 
base station controller (BSC) to page the mobile in each of the 
cells it might be currently in. The VLR keeps a record of the 
current cells (or groups of cells, really) which is updated 
regularly by signals from the mobile as it moves around and 
checks signal strength with the surrounding radio masts.

> ObUA:  Are all the advances in telecommunications a means of an unknown
> avatar of the Messenger to outdo Dermott Arkane?  If so, it doesn't seem
> to be working.  Or maybe it weakens the power of *all* the Messengers by
> making every cell phone and internet user a "mini-messenger".

	The mobile makes everyone a messenger, a journalist on 
the spot and a member of a tribe all at once. Once bandwidth 
issues are solved to allow realtime video over the phone 
we'll see all sorts of immediate eyewitness amateur journalism 
that could have interesting effects. Better and faster than 
a handcam: what's that do for riots and war reporting?


--
Myles Corcoran - 023 20469 (w) - 023 20481 (fax) - 021 4503904 (h)   
Alcatel Ireland Ltd., Bandon, Cork, IRELAND - myles at ck.cit.alcatel.fr
 "Memes don't exists - tell you friends" - Strange Company

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