Lee Scargall

Lee is group director of enterprise risk management, with overall responsibility for revenue assurance, fraud, risk management, financial controls, and finance systems at Qtel Group. Based at the head-office in Qatar, Lee provides the leadership and strategy for Qtel Group's 16 business units, covering a combined subscriber base of 83 million people across Middle East, North Africa, and Asia. Lee has over 15 years experience of the telecommunications industry, holding previous positions as Head of revenue assurance and risk management at Cable & Wireless, and also as business development manager at T‑Mobile, UK. Lee has also been employed by Deloitte Consulting, working on projects for both mobile and fixed-line operators across Europe and the US. Lee was awarded a PhD in Electrical and Electronic Engineering from the University of Newcastle upon Tyne, UK, for advanced research in to 3G video-telephony.

Congratulations to all those who got the answer correct for LTT-07. They are Wessel Scheepers, Sriram Dharmarajan, Arun Rishi Kapoor, Kamal Khattar, Michael Lazarou, Jeeson Thekkekara, and Guy Howie. 

Analysis of the billing suspense file reveals there is one test call in there, so answer A = true.

4487878712326, 4487878712336, 14/07/2013, 10.41:07, 00:00:20, No rate plan

A further analysis of the mediation suspense file reveals there is also one test call in there, so answer B = true.

_____________, 4487878712338, 14/07/2013, 10.43:09, 00:00:40

And analysis of the consolidated MSC1,2,3 switch file, reveals the remaining test calls were not recorded by any of the MSCs, so it is possible there could be a hidden switch, so answer C = true. Therefore, the right answer is D = (A+B+C).

The next LTT will be published on Monday 19th August.

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Welcome to this month’s LTT.

The Challenge

ACME test call generators have convinced your CFO to accept a free trial of their latest product – the “mobile-mobile TCG analyzer”. Their latest product is branded mobile-mobile because it fits in to the back of a car and allows a mobile operator to test call scenarios across its network from different switch locations. The sender and receiver are housed in the same unit in the back of the car, and it streams near real-time data back to ACME’s head-office for reconciliation against a filtered feed from the billing system.

A schematic of the network diagram is shown below. It shows there are three MSCs, a mediation platform, and a combined rating and billing system. There are two suspense buckets (highlighted in red), where CDRs are dropped for reprocessing [please click on the picture to enlarge].


You receive a call from the ACME account manager alerting you to some missing test call CDRs in the feed from the billing system. The ACME TCG confirms a series of test calls were successfully made between 10.40am and 10.55am on 14 July but were not billed. The CFO asks you to investigate and to report back to him with your findings after lunch.

You have access to the following: The ACME reconciliation report, Billing suspense, Mediation suspense, and a combined MSC1-2-3 switch file.

What would be your answer to the CFO?

  • A – The missing CDRs have dropped in to the billing suspense bucket.
  • B – The missing CDRs have dropped in to the mediation suspense bucket.
  • C – There could be a hidden switch in the network, or
  • D – (A + B + C).

To receive the answer, please send an email to quiz@talkRA.com with LTT-07 in the heading. The next LTT will be published on Monday 19th August.

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This month’s wining answers came from Sriram Dharmarajan at Protiviti, and Srinivas Chikkala from India.

To solve LTT-04, the data from the 4 systems had to be joined together using the IMSI and MSISDN, and filtered with the required parameters i.e., ["A", "01", ("precept 250" or "precept 500" or "precept 750")]. There were also inconsistencies between the “names” in the provisioning and billing systems, that needed some manual reconciliation.

The correct answer was L Berselli, which is illustrated in the attached file.

The next LTT will be published on Monday 20th May.

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Welcome to this month’s lunch time teaser; A practical RA problem, which is solvable within a 30 minute lunch break.

The challenge

An audit using a test call generator showed in some circumstances it is possible to make voice calls without being charged. The CFO asks you to look in to it and tells you to report back with your findings within 30 minutes.

There are four sets of data available to you, as outlined in the diagram below.

The file from the provisioning system contains the “customer’s name” and the “MSISDN”.

The file from the HLR contains the ”IMSI”, the ”network status” (NWS) which has the following definitions:
A = Active
B = Barred on the network
C = Cancelled on the network

And the “service type” (SER_TYP) 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 file from the rater contains the “MSISDN” and the “tariff plan” information.

And the file from the billing system contains the “customer’s name” and the “IMSI”.

The audit found that “active” customers on the precept 250, 500, and 750 tariffs, and with a “service type” = 01, could make unlimited free calls. The challenge is to identify the name of the customer(s) who this relates to, so your company can send them a back-dated bill.

Please email your answers to lee@talkRA.com  - the answer will be revealed in two weeks time, along with the names of the first three correct answers.

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This month’s correct answers came from three times winner Lionel Griache at ProactiveRA, and Srinivas Chikkala from India.

To solve LTT-03 some basic CDR reconciliation matching between MSC1 & MCS2, to the interconnect I/C Gateway was required. The results would show there are some CDRs present at the interconnect I/C Gateway, but are not present on MSC1 or MSC2. The missing CDRs correspond to off-net calls with a short duration of under 5 seconds.

Browsing through the CDR data of both MSC1 & MSC2 shows there are no calls under 5 seconds of duration, which indicates the problem could also include on-net calls as well. Although it is not possible to determine if the calls originated from either MSC1 or MSC2, the lack of calls under 5 seconds in them both points to the problem being in the two switches. Therefore, the most likely cause of the revenue leakage will have to be answer C – MSC1 & MSC2.

The next LTT will be published on Monday 15th April.

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