As shipped, Pycom modules only support CAT-M1, in order to use NB-IoT you need to flash a different firmware to the Sequans modem. Instructions for this can be found here.
At the moment the NB-IoT firmware supplied by Sequans only support Ericsson base stations configured for In-Band mode. Standalone and guard-band modes will be supported in a later release. Support for Huawei base stations is also limited and only lab testing with Huawei eNodeB is recommended at the moment. Full support for Huawei is planned for early Q2 2018.
for example with Vodafone:
from network import LTE lte = LTE() lte.send_at_cmd('AT+CFUN=0') lte.send_at_cmd('AT!="clearscanconfig"') lte.send_at_cmd('AT!="addscanfreq band=20 dl-earfcn=6300"') lte.send_at_cmd('AT!="zsp0:npc 1"') lte.send_at_cmd('AT+CGDCONT=1,"IP","nb.inetd.gdsp"') lte.send_at_cmd('AT+CFUN=1') while not lte.isattached(): pass lte.connect() while not lte.isconnected(): pass # now use socket as usual...
IMPORTANT: Once the LTE radio is initialized, it must be de-nitialized before going to deepsleep in order to ensure minimum power consumption. This is required due to the LTE radio being powered independently and allowing use cases which require the system to be taken out from deepsleep by an event from the LTE network (data or SMS received for instance).
When using the expansion board and the FiPy together, the RTS/CTS jumpers MUST be removed as those pins are being used by the LTE radio. Keeping those jumpers in place will lead to erratic operation and higher current consumption specially while in deepsleep.