Lunch Time Teaser – 01

Welcome to this month’s lunch time teaser; A practical RA problem, which is solvable within a 30 minute lunch break. So why not see if you have the skills to solve the problem? Sadly, there is no prize but I will publish the names of those able to provide the correct answer.

The challenge

There are four sets of data that need to be reconciled to solve the problem.

The first file contains the link between the MSISDN, IMSI, and Account Number. The second file contains the “service type”, which is a binary flag with the following definitions:
• 00 = Incoming voice calls only
• 01 = Outgoing voice calls only
• 10 = Data calls only
• 11 = Voice calls and data

The third file contains the “network status”, which has the following definitions:
• A = Active
• B = Barred on the network
• C = Cancelled on the network

And the fourth file contains the subscriber’s prepay “balance”.

The rules are simple, in order to make a voice call, the subscriber should be “active” on the network, have the appropriate “service type”, and also have balance available. The challenge is to work out the MSISDN of the subscriber that is theoretically able to make a voice call.

Please email your answers to  – the answer will be revealed in two weeks time.

Lee Scargall
Lee Scargall
Lee is a senior risk management professional. He has extensive experience of managing both ERM and RAFM teams in telcos around the world, having worked for Ooredoo Group, Cable & Wireless and T‑Mobile UK.

Lee earned a PhD in Electrical and Electronic Engineering from the University of Newcastle upon Tyne, UK, for advanced research in to 3G video-telephony.