Remote Rig

RRC 1258 Support in English => General discussion forum => Topic started by: K5DN on 2010-07-17, 19:38:14

Title: GSM codec available?
Post by: K5DN on 2010-07-17, 19:38:14

Is the GSM or other low bandwidth codec available for the 1258mkii?  What would be the data rate with overhead be?  For some wireless isp's in this area, even the lowest rate G711 is a problem.

Bob
K5DN

Title: Re: GSM codec available?
Post by: sm2o on 2010-07-21, 09:41:31

No there is no GSM-Codec available. GSM codecs is not good for this kind of product. GSM-codec adding latency and is not handling low signal to noise ratio signals very well, which is normal on HF. At least in Europe 80kbit/s is no problem in mobile networks, the problem is more often the latency which can be 200-300 ms in worst case.

73 de mike

Title: Re: GSM codec available?
Post by: K5DN on 2010-07-21, 21:11:54

Thanks for the info.

Does the 1258 switch from transmit to receive audio (half duplex) to conserve bandwidth?  Some software solutions I have tried (IPsound) do not; a big waste of bandwidth.

Bob

Title: Re: GSM codec available?
Post by: sm2o on 2010-07-21, 23:20:53

Yes, the default settings is simplex, the audiostream is controlled by PTT. But if the VOX is used there are audiostreams in both directions.

73 de mike