Cellular Network Infrastructure

Both test cases are broken since build#949 [1][2]:

Dynamic test case error: While RAW-decoding type '@GSM_SystemInformation.SystemInformation':
There is not enough bits in the buffer to decode type @GSM_RestOctets.UTRAN_GPRSMeasParamsDescOpt.presence.

I think this regression is caused by [3]. The problem is that in ttcn3-bts-test, SI2quater contains a list of UTRAN neighbor cells, that is currently not implemented in SI2quaterRestOctets. The coding of this list is quite complex (more complex than the E-ARFCN list), and would probably require us to implement some parts in C++. As a quick work around, we could avoid calling dec_SystemInformation() on SI2quater in f_l1_sample_si().

[1] https://jenkins.osmocom.org/jenkins/view/TTCN3/job/ttcn3-bts-test/949/
[2] https://jenkins.osmocom.org/jenkins/view/TTCN3/job/ttcn3-bts-test/949/artifact/logs/bts-tester/BTS_Tests.TC_si_sched_13_2bis_2ter_2quater.merged
[3] https://gerrit.osmocom.org/q/I879c37eb51ece55d79346c6bf1a4951c3f11c77e