Evaluation of Quality of Service Key Performance Indicators for M-tel Network of Area Vi Kaduna
CHAPTER ONE
PREAMBLE TO THE STUDY
When Nigeria gained her independence in 1960, there were only 18,724 functional telephone lines for an estimated population of 45 million which was a teledensity ratio of 0.04 telephones per 100 people. According to the International Telecommunication Union (ITU), by 1966, Nigeria teledensity ratio was a mere 0.36 and 0.4 by (1999). According to the Nigerian Communication Commission (NCC), Nigeria’s teledensity is a far cry from the African average of 1.67. However, with the liberalization of the telecommunication industry in Nigeria the story changed dramatically with the teledensity ratio tripling within just one year of Global System for Mobile Telecommunication (GSM) operation. By May 2005 Nigeria with an estimated population of over 120 million had more than 9 million Global System for Mobile Communication (GSM) subscribers, making the country one of the fastest growing GSM market, in the World. At the moment, there are about 40 million subscribers with just four fully functional GSM operators in Nigeria; Mobile Telecommunication Network (MTN), Celtel, Glo mobile telecommunication and Mobile Telecommunication (M-tel) while others like Mubaddalah and Alheri have recently been given licenses to start operations. Four years after the start of the GSM era in Nigeria, the focus is gradually shifting from providing coverage to providing quality service. The euphoria of owning a phone set is gradually giving way to complaints of dropped calls and congestion. The operators are fast realizing that they are in a highly competitive environment, where dissatisfaction by subscribers may give rise to high rate of subscriber reduction and low revenue for the operator.
CHAPTER TWO
MOBILE TELECOMMUNICATION (M-TEL) NETWORK STRUCTURE
INTRODUCTION
The design of the network involved the building of eleven Mobile Switching Centre (MSC)/ Base Station Controller (BSC) nodes and five hundred and seventy nine Base Transceiver Stations (BTS) nationwide with a combined capacity of 1.2 million subscribers.
Node- interconnections, according to the relevant standards, are supported by Erickson switches. The entire networks have gateway mobile switching centre (GMSC) functionality. The Intelligent Network (IN) comprising the billing gateway (BGW), prepaid administrative system (PPAS), the signal control point (SCP), the interactive voice response (IVR) nodes as well as the centralized nodes consisting of the voice mail system (VMS), short message system (SMS), and the service data point (SDP) are all supported by Erickson equipment, There will also be three home location register (HLR) nodes (one per vendor) with 512,000 subscriber licenses per HLR, while each HLR node interconnects every signal transfer point (STP) in the network for full redundancy. The required transmission and signaling links between the network nodes are also specified according to the International Telecommunication Union (ITU-T) standards as in figures 2.1 to 2.4 [3].
CHAPTER THREE
QUALITY OF SERVICE IMPROVEMENT
INTRODUCTION
Network improvement serves the objectives for a maximum application of network resources and the improvement of the quality of service. These contribute to the foundations of future network expansion. Improvement here refers to a sound implementation of network planning. Quality of service improvement can be achieved by expanding the coverage area and by optimally utilizing the available resources on both the access and the core network parts. An “improved” network: increases network availability and efficiency, and it increases subscriber satisfaction by improving the overall network quality. It also increases competitiveness and reduces operational costs [7, 9 ].
PROCESSES OF NETWORK IMPROVEMENT
The mobile communication network of GSM generally falls into mobile switching- transporting part and radio part. Due to the mobility of subscribers and the complexity of radio waves in propagation, the radio part always becomes the decisive factor affecting the quality of service (QoS) of the GSM network. Wireless network improvement refers to reasonable modification to planning and designing of communication networks according to certain principles so that a more reliable, more economic network operation, a higher quality of service (QoS), and a higher utilization ratio for network resource can be achieved. Undoubtedly, this is of great significance for network operators and subscribers.
CHAPTER FOUR
KEY PERFORMANCE INDICATORS (KPIS)
INTRODUCTION
Performance of the improvement function is typically measured for operational control purposes. Since improvement also has a strategic dimension, its performance measurement system should be linked to the strategy of the function in order to get the maximum impact. This chapter presents a structured approach and definitions of some of the factors affecting the key performance parameters of the GSM network. The measurement system features a balanced scorecard composed of key performance indicators (KPIs). The key parameters of the base station controller (BSC) are used [16].
CHAPTER FIVE DATA ANALYSIS
M-TEL KADUNA AREA VI
The M-tel Area VI Kaduna switch is made up of one mobile switching centre (MSC), one base station controller (BSC), and ninety nine base transceiver station (BTS). It also has one visitor location register (VLR), two operation and maintenance center (OMCR), one for the MSC and the other for the BSC, where the data used for this thesis were obtained.
CHAPTER SIX CONCLUSION
INTRODUCTION
M-tel Nigeria Limited is one of the licensed GSM companies in Nigeria. The company utilizes the GSM technology employing both frequency division multiple access (FDMA) and time division multiple access (TDMA) for mobile telephony. The main features of GSM are mobility, roaming and data messaging. Giving the versatility of the GSM technology.
The place of Quality of service improvement in a GSM network can not be overemphasized because it goes a long way to confirm the reliability of the network. It also ensures that the subscribers in the network retain the services of the network and there is a high possibility of more subscribers coming to the network. Though a rigorous and time consuming exercise, it is a very important aspect of the GSM network. It can be visualized as a GSM maintenance tool used for tuning up the network and also identifying and removing bottlenecks (congestion, interference, call drop etc) from the network.
SUMMARY OF RESULTS
A study on Quality of service carried out at the Kaduna M-tel Switch has shown ( from the data collected) most of the faults occur at the Abis and the A interface, link between the Base Transceiver Station (BTS), the Base Station Controller (BSC) and the Mobile Switching centre (MSC) respectively. The faults include power outage, malfunctions of some components and modules in both the BSC and BTS rack, lack of cooling systems in both BTS and repeater stations. In the BTS side there are faults like call drop as a result of poor handover which also occurred frequently. Network system must perform reliably in the face of fierce competition as success or failure will be the direct impact of customer satisfaction.
SIGNIFICANCE OF WORK
This thesis serves as a useful tool for the performance improvement of M-tel Nigeria Limited and also to test the quality of service for any other GSM operators. It is common knowledge that the GSM subscriber population density has been on a rapid increase from the inception of the technology. At the last count, the total subscriber density is about twenty – five million. As observed, Quality of service improvement is carried out to identify the following bottlenecks experienced in the network and proffer solutions to them: congestion, call drop, poor hand over and black spots. The results have shown that there is a complete neglect by the network over these issues, and there are no prompt responses to faults on the network.
The advantages of Quality of service are so enormous that it can not be overlooked. When done on a periodic schedule, it tunes up the network. The application of the results obtained can also be used to determine the overall subscriber base of the network
LIMITATION
Unavailability of data from other GSM operators to make comparison, as their Quality of service data were classified as top company secret, this is because the data can be used to determine the overall performance of these networks. Also there was the unavailability of tools in obtaining and analyzing the data in this thesis.
CONCLUSION
All the causes of every fault have been identified and solutions for better performance have equally been proffered. The analysis of data obtained from the Operation and Maintenance Center for– Radio (OMCR) using bar and line charts inferred that the M-tel network performance in Kaduna zone needs to be improved with emphasis placed on the Quality of service improvement exercise, continuous training of operation staff as well as finding a lasting solution to the power outages in the BTS and repeater stations. The result obtained from this thesis shows how gradually the network traffic reduced from 1100 (Erlang) to less than 200 (Erlang) as shown in fig 5.9. The result also shows a frequent call drop in the six months period, even though for the month of March to May 2006, the result was considerably fair. But it worsened for the months of June to August 2006 as in fig 5.8. The SDCCH in service rate was good for the months of March to May 2006, but was poor for the months of June to August 2006 as in figure 5.1. Also the SDCCH in congestion rate for June to August 2006 was very poor (above 15%) but comparatively better for the months of March to May 2006 as in fig 5.2. Both the hand over and dual handover success rates for the six months period is fair (above 70%), even though the threshold is >95% as in figures 5.3 and 5.4.The radio switch rate was also good for the five months period above 90% but very poor for the month of August 2006 as shown in figure 5.7. TCH in service rate was better for the months of June to August 2006, but fair for March, April and May 2006 as in figure 5.6.
RECOMMENDATION FOR FURTHER WORK
- This investigation is only on some few parameters for voice measurement. For further work, other parameters should be studied and they should include; call completion rate, minimum call setup time, maximum call setup time, speech quality, number of blocked calls, and locationupdates
- Data measurement should also be included in further investigation such as in GPRS radio link parameters, with respect to reliability, throughput anddelay
- Quality of service comparison with other operators should also be encouraged in further
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