Hi all, I consider a GSM900 2G implementation using the USRP2-N200. I would like to know how many channels/AFRCN/sub carriers (of 8 slots each) does the USRP2-N200 support? If the number of supported channels is more than 1, what is the technique that the USRP2-N200 use to transmit multiple channels on single transmitter? If the answer is single channel, is there a USRP type that support more than one channel? Best regards, Amit.

Amit - The USRP is ignorant of the concept of 'channels', as you talk of them. You get 25 MHz of baseband, and you can process that bandwidth however you want. So ignoring inter-channel interference and such, assuming 200kHz GSM channels, you could split your bandwidth into (25e6 / 200e3) = 125 channels. That said, if you are using OpenBTS, I think OpenBTS only supports one channel at a time? The limitation, however, is not the USRP. Cheers, Ben ---------------------------- Ben Hilburn <http://goo.gl/5DdZ3> @ Ettus Research, LLC<http://www.ettus.com/> On Thu, Feb 9, 2012 at 4:17 AM, Amit Nevo <Amit.Nevo@hallo.co.il> wrote: > Hi all,**** > > ** ** > > I consider a GSM900 2G implementation using the USRP2-N200. **** > > ** ** > > I would like to know how many channels/AFRCN/sub carriers (of 8 slots > each) does the USRP2-N200 support?**** > > ** ** > > If the number of supported channels is more than 1, what is the technique > that the USRP2-N200 use to transmit multiple channels on single > transmitter? **** > > If the answer is single channel, is there a USRP type that support more > than one channel? **** > > ** ** > > Best regards,**** > > ** ** > > Amit.**** > > _______________________________________________ > USRP-users mailing list > USRP-users@lists.ettus.com > http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com > >

On Thu, Feb 9, 2012 at 7:17 AM, Amit Nevo <Amit.Nevo@hallo.co.il> wrote: > > Hi all, > > I consider a GSM900 2G implementation using the USRP2-N200. > > I would like to know how many channels/AFRCN/sub carriers (of 8 slots each) does the USRP2-N200 support? With 25 MHz of bandwidth of the N200 you can digitize the entire (non-extended) GSM900 uplink or downlink if that's what you're interested in. As Ben said, the device views samples and bandwidth and not specific GSM channels. > If the number of supported channels is more than 1, what is the technique that the USRP2-N200 use to transmit multiple channels on single transmitter? > > If the answer is single channel, is there a USRP type that support more than one channel? Multiple channels can be supported using a channelizer / transmultiplexer with a single device. Support for that capability in the open version of OpenBTS is forthcoming. Thomas