Convergence of Mobile and Fixed networks and “Number Portability”

1. From the technology and business perspective, the differentiation between Mobile Networks and Fixed phone network is slowly diminishing. Voice, Mobile Data / Internet characteristics in Mobile systems are similar to these in Fixed Networks.  Differences are the access type, bandwidth limitations and device characteristics. Therefore, it is necessary to focus on the convergence of Fixed and Mobile networking so to provide Universal mode of Telecommunication for all.  

2. Product utility in Mobile situation: Higher data rates of 2 Mbps and above, is required only for quick down loading of high volume contents such as a lengthy digital movie etc. The utility of such services will be rare in a mobile situation and therefore, cannot become a major revenue earning product. Such high volume data files can be easily carried in plug and play storage devices. 

It can be seen that an assured data rate of 384 to 512 Kbps, is more than adequate for good quality user intensive  'real time' video plus voice  products such as,  TV news, digital movie display, Multi-media transactions over internet etc. With 384 to 512 Kbps data rate, the data service can be delivered to the mobile device in a vehicle moving at its normal speed without compromising quality of service.

 3. The business viability of high data service: Higher data rates of 2Mbps and above in Mobile network any time, anywhere is near to impractical in terms of  business viability.  It could be realized only in limited hot spots and the Mobile device in more or less stationery situation identical to Wired phone.

4. Limitation in current Wired Line devices. Though very high data rate products could be made available in a fixed network system, the fixed network provides only limited mobility within a short coverage area.  High data rate need of the user can be realized if the user can plug in his device to a fixed network socket or get serviced through a PON connectivity as the end link at the premises.

4.1. Band width on demand.  This can be achieved with a fixed network switching system that can identify and give the needed service to the user the same way as done in the mobile switching system.

5. Convergence of Wired and Wireless network and systems:  There are already dual mode devices that can work in fixed network and mobile networks. Also the function of the switching systems of fixed and mobile networks could be identical except for the mode of line termination at the user and switching system end.

6.  "Number Portability” by Roaming feature in Wired Network”

In GSM / CDMA every ‘user’ is technically in "Roaming" condition in the local network even while the mobile is stationery.  It is possible to use the same concept and systems combined for both mobile and fixed lines. There are already such "COMBI” switches in use. In effect, the fixed line devices also will be SIM enabled and are registered in the HLR and VLR of the system as in the case of to mobile phones.  This way, the fixed line terminal also will be in roaming condition like the mobile phone.  

6.1. The differences are only in the connectivity at the user end, in the system end and the physical media. Instead of entering the switching system via the Trans-receivers as 16 kbps stream, the fixed lines voice streams will enter as 64 kbps streams and switched through the same switch. PON can give higher data rate connectivity to the fixed lines. The customer need to only carry a plug in type portable SIM that can be plugged into any fixed line device, connected to such systems anywhere to log in and avail the service.

Such an arrangement will provide full “Number Portability” to fixed line service and readily provide service on the spot across the world.  

Author: Abraham Paul, MD FCOMNET. 

Ex. V.P. Technical sales Siemens SPCNL, India / Director, Siemens ICN RHQ UAE / G.M. BPL Mobile India / TES DoT India.