GSM license approval for HAR2009

Harald Welte laforge at
Thu Jul 23 09:40:34 CEST 2009

On Thu, Jul 23, 2009 at 08:43:26AM +0200, Dieter Spaar wrote:
> Hello Harald,
> On Wed, 22 Jul 2009 23:49:00 +0200, "Harald Welte" <laforge at> wrote:
> > 
> > Even with two BTS at two TRX (exercising all our four ARFCN), the total call
> > capacity is not more than 13 simultanesous MS-to-MS calls (since each call
> > requires two timeslots).  Yes we could do half-rate, but we have no software
> > support for that so far.
> You have the adjacent channels 121 to 124 for GSM 900 ? As far as I am
> aware, adjacent channels will disturb each other. From what I know,
> real networks usually have one free guard channel in between. So at
> least the configuration of using adjacent channels should be checked
> in advance (but you don't know how well different phones behave).

yes, we should check that in advance.  Also, if we have two BTS at different
geographic locations, we might very well have 121 + 123 for one, and 122 + 124
for the other one.

For testing it is probably sufficient to use two adjacend channels on two TRX's
of one BTS.

- Harald Welte <laforge at> 
"Privacy in residential applications is a desirable marketing option."
                                                  (ETSI EN 300 175-7 Ch. A6)

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