This commit introduces CSFB (circuit switched fall-back) capabilities to
srsLTE. Actually, all the eNB has to do is to send a
RrcConnectionRelease with the RedirectedCarrierInfo IE.
The MME triggers this by the S1AP CS Fallback Indicator IE, which may
be present either in the Initial Context Setup Requst or in the
UE Context Modification Request.
As srsLTE has no support for the UE Context Modification Request at all
yet (!), basic support for this message is introduced in this patch.
Both Mobile Originated and Mobile Terminated CSFB with a coupel of
different UE models have been verified using this patch in a setup
consisting of srsENB attached to an undisclosed EPC connected via SGsAP
to a complete Osmocom 2G network.
Closes: #358Closes: #363
* first step towards moving MAC timers to stack. Mac is still using its own timers. srslte::timers class can be restructured.
* moved timers out of the UE MAC
This adds the required missing bits to the eNB config file parser
to enable minimalistic support of parsing SIB7 configuration.
SIB7 contains GERAN (GSM) neighbor cell information, which is important
if you are operating a combined 2G+4G netowrk and want to assist the UEs
to reselect GSM cells once they move out of LTE coverage.
An example SIB7 section looks as follows:
sib7 = {
t_resel_geran = 1;
carrier_freqs_info_list =
(
{
cell_resel_prio = 0;
ncc_permitted = 255;
q_rx_lev_min = 0;
thresh_x_high = 7;
thresh_x_low = 7;
start_arfcn = 871;
band_ind = "dcs1800";
explicit_list_of_arfcns = ( 873, 875, 877 );
}
);
};
Closes: #357
The documentation talks about a MAC protocol trace, but in fact
it is only a protocol trace of dedicated channels. There's a related
define in the source code, but that's not documented.
Let's at least make the user aware that the MAC pcap trace is
for dedicated channels only, unless he uses that #define.