EHS6 localization by GSM cells | Thales IoT Developer Community
July 24, 2018 - 12:01pm, 3992 views
I need to implement a localization service by EHS6 module. We don't have a possibility to use GPS, so we need to use cell information to do the task.
So I need to get the following information about cells around - CID (cell ID), LAC, RSSI and if possible MCC and MNC.
There are two commands which give such an information:
1. AT^SMONP - it works just fine but only for 2G cells. But normally in urban area most of the cells are 3G. In this case the command returns an information which is not usable for cell indentification:
UARFCN1,PSC1,EC/n01,RSCP1,SQual1,SRxLev1 - not a usable cell id information.
2. AT^SNMON - it returns a prety usfull information for cell indentification. But it cannot be used when device is registered to the network. So it's not usable for continous tracking when device is connected.
So what I can do to receive a proper 3G cell indentification information (CID, LAC, MCC, MNC) when the device is registered to network?
There are a very good options for EHS6, see:
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You are right about AT^SMONP and AT^SNMON commands. That's how they work. You can always get the information about the serving cell with AT^SMONI command. But this is probably not enough for you. EHS6 module should have a cell based position implemented - please see at^srvctl command ("CBL").
EHS6 supports cell based position via at^srvctl command - this is TRUE. But it locked to use only Comabin service, which limits the usage. For example I want to use google service, other paid service or even some of the free servers available on the web.
But for this I need a simple info - just to have proper 3G network cell infos. That's why is so strange for me - in fact I cannot get cells IDs (except of the connected one) in case of 3G. Which sounds .... "stupid". Did I miss something???
I have some expiriance with other modules suppliers - they don't have such a sort of limitations.
Following the AT Command Set the AT^SMONI command returns that what you need:
ME is camping on a UMTS (3G) cell:
Syntax: ^SMONI: ACT,UARFCN,PSC,EC/n0,RSCP,MCC,MNC,LAC,cell,SQual,SRxLev,,Conn_state
Example: ^SMONI: 3G,10564,296,-7.5,-79,262,02,0143,00228FF,-92,-78,NOCONN
There is CID (cell), LAC, MCC and MNC.
Correct me, If I am wrong but:
AT^SMONI returns information only for the currently cell. It's not possible to get an accurate position information via one cell only.
^SMONI returns information only for the current cell - not enough for positioning.
^SMONP returns information for neighbour cells,- but in case of 3G network returned information is not usable for positioning.
AT^SNMON returns usable information - but the device must be UNregistered from the network.
at^srvctl - works only with Combain server.
So in fact we don't have a clear way to perform a positioning via cell network with EHS6. Most of the competitors don't have such a restrictions. In fact for mostly strange is ^SMONP command. Why it hides the cell ID and LAC in case of 3G network...
You are right. EHS6 works that as you desribed. So you will have to choose what way will be the best for you. If it possible maybe better will be unregister EHS6 from the network, scan every cells and then connect to network and send data to your sevice. Ofcourse if it possible to disconect your connection.
Can you try to do this or I'm thinking on wrong way?