From Forum Nokia Wiki

ID	TSS000644	Creation date	May 10, 2007
Platform	S60 2nd Edition, FP2 and FP3	Devices
Category	Symbian C++	Subcategory	Networking, Telephony

Keywords (APIs, classes, methods, functions):

Overview

Retrieving current network information on S60 2nd Edition, Feature Pack 2 devices

Description

CTelephony API is supported only from S60 2nd Edition, Feature Pack 3 onwards. Even though the API (etel3rdparty.h) is present in the S60 2nd Edition, Feature Pack 2 SDK, it is not supported by S60 2nd Edition, FP2 devices (Nokia 6630, Nokia 6680).

Solution

Symbian provides a Mobinfo 3rd Party Telephony Library for devices based on Symbian OS v7.0, v7.0s, v8.0a, and v8.1a.  With Mobinfo, 3rd parties can get information about
    * IMEI, IMSI, and own phone numbers
    * Network availability and change notification
    * Network and location identification
    * Battery and signal strength notification
Mobinfo is provided as a public, redistributable library. It can be downloaded from
https://developer.symbian.com/wiki/display/pub/Symbian+OS+system+libraries
To make use of the API, you need to utilize two headers (mobileinfo.h, mobinfotypes.h) and a single library, mobinfo.dll.
Mobinfo API itself consists of three main classes
    CMobileInfo
    CMobileNetworkInfo
    CMobileContext
Asynchronous methods from Mobinfo should always be used via active objects (the client must derive from CActive).
For example, retrieving current network information:
    CMobileNetworkInfo::GetCurrentNetwork( TMobileNetwork& aMobNetInfo, TRequestStatus& aStatus );
GetCurrentNetwork returns information about the network the handset is currently registered on. aStatus will be completed with KErrAccessDenied when in flight mode.