An Improved Model for Key Performance Indicators Analysis for Mobile Number Portability Scheme for GSM Subscribers in Nigeria
Chapter One
Aims and Objectives of the Work
This research is aimed at developing an improved model using MNP scheme for GSM subscribers vis-a-vis their KPIs using Fuzzy logic blockset having identified the performance of Mobile Cellular Networks in Nigeria. Other Specific objectives include:
- To carry out empirical analysis on the GSM networks KPIs as well as analysing the data collected using drive test approach.
- To demonstrate migration algorithm using the reference architectural JAVA based VSim MNP suite for GSM network integration.
- To develop a prototype GSM module for MNP which demostrates a good BER perfomance depicting an excellent QoS results
- To use fuzzy logic to detect the network with the best KPIs.
CHAPTER TWO
LITERATURE REVIEW
Introduction to GSM Telephony
According the website, GSM (Global System for Mobile Communications),was defined as a standard set developed by the European Telecommunications Standards Institute (ETSI) to describe protocols for second generation (2G) digital cellular networks used by mobile phones[12]. The GSM standard was developed as a replacement for first generation (1G) analog cellular networks, and originally described a digital, circuit switched network optimized for full duplex voice telephony. This was expanded over time to include data communications, first by circuit switched transport, then packet data transport via GPRS (General Packet Radio Services) and EDGE (Enhanced Data rates for GSM Evolution or EGPRS). Further improvements were made when the 3rd Generation Partnership Project (3GPP) developed third generation (3G) UMTS standards followed by fourth generation (4G) LTE Advanced standards [12].
The mobile radio network technology family of the 3GPP as well as its predecessor ETSI (European Telecommunications Standards Institute), including GSM/EDGE (Global System for Mobile communications/ Enhanced Data rate for GSM Evolution) and UMTS/HSPA (Universal Mobile Telecommunication System/ High Speed Packet Access) technologies, now accounts for over 85% of all mobile subscribers worldwide. The further increasing demand on high data rates in new applications such as mobile TV, online gaming, multimedia streaming, etc., has motivated the 3GPP to work on the long term evolution (LTE) project since late 2004. Overall target was to select and specify technology that would keep 3GPP’s technologies at the forefront of mobile wireless well into the next decade [13].
GSM Carrier Frequency
GSM networks operate in a number of different carrier frequency ranges (separated into GSM frequency ranges for 2G and UMTS frequency bands for 3G), with most 2G GSM networks operating in the 900 MHz or 1800 MHz bands. Where these bands were already allocated, the 850 MHz and 1900 MHz bands were used instead (for example in Canada and the United
States). In rare cases the 400 and 450 MHz frequency bands are assigned in some countries because they were previously used for first-generation systems. Most 3G networks in Europe operate in the 2100 MHz frequency band.
Regardless of the frequency selected by an operator, it is divided into timeslots for individual phones to use. This allows eight full-rate or sixteen half-rate speech channels per radio frequency. These eight radio timeslots (or eight burst periods) are grouped into a TDMA frame. Half rate channels use alternate frames in the same timeslot. The channel data rate for all 8 channels is 270.833 kbit/s, and the frame duration is 4.615 ms. The transmission power in the handset is limited to a maximum of 2watts in GSM 850/900 and 1 watt in GSM 1800/1900 [12].
According to [14], the demand for wireless communication had grown rapidly and the capacity of cells in the existing digital cellular mobile networks, like GSM, need to meet the increased demand. The work observes that the network operators are now facing the problem of how to increase the capacity of an existing network without noticeable degradation of quality of service. In this case different solutions have been foreseen but the most obvious solution in place has been that of extending the GSM band or increase the number of serving channels or frequencies in an area. However the overall available GSM spectrum is limited and is usually divided between 2 or 3 network operators leaving a spectrum of not more than 10 MHz for each operator [14]. Before expanding more on the review issues of GSM QoS, a review of the various GSM cellular networks will be presented below.
GSM Network Technologies and Their Evolutions
After the first generation-1G GSM network comes Second Generation-2G , Third Generation- 3G Evolution and Post-3G Future Generations.
Post-3G Future Generations will be presented below as the 4th, 5th and next generation Evolutions.
Fourth Generation- 4G Evolution
The 4G refers to International Mobile Telecommunications Advanced, (IMT-Advanced), as defined by ITU-R [25]. According to[26], in telecommunications, 4G refers to the fourth generation of mobile phone mobile communication technology standards which is a successor of the (3G) standards. A 4G system provides mobile ultra-broadband Internet access, for
example laptops with USB wireless modems, to smart phones, and to other mobile devices. Conceivable applications include amended mobile web access, IP telephony, gaming services, high-definition mobile TV, video conferencing, 3D television and Cloud Computing [26].
In the world today, two 4G candidate systems are commercially deployed: the Mobile WiMAX standard (at first in South Korea in 2006), and the first-release Long Term Evolution (LTE) standard (in Oslo, Norway since 2009).
In September 2009, the technology proposals were submitted to the International Telecommunication Union (ITU) as 4G candidates [29].
Basically all proposals in 4G are based on two technologies:
- LTE Advanced standardized by the 3GPP
- 802.16m standardized by the IEEE (i.e. WiMAX)
In Nigeria, the implementations of Mobile WiMAX and first-release LTE is largely considered a stop gap solution that will offer a considerable boost until WiMAX 2 (based on the 802.16m spec) and LTE Advanced are deployed. Though, the latter’s standard versions were ratified in spring 2011, but are still far from being implemented [27]. A summary of the technologies that have been studied as the basis for LTE Advanced is included in a technical report in [30].
IMT-2000 compliant 4G standards
These includes viz:
LTE Advanced
The Long Term Evolution Advanced (LTE-A) is essentially an enhancement to LTE network. It is a candidate for IMT-Advanced standard, formally submitted by the 3GPP organization to ITU- T in the fall 2009, and expected to be released in 2013 [26]. LTE-A offers an upgrade path that makes it more cost effective for vendors to offer LTE and then upgrade to LTE Advanced which is similar to the upgrade from WCDMA to HSPA. It is observed that LTE and LTE Advanced will make use of additional spectrums and multiplexing to allow it to achieve higher data speeds [31]. Coordinated Multi-point Transmission will also allow more system capacity to help handle the enhanced data speeds. Release 10 of LTE is expected to achieve the IMT Advanced speeds.
Release 8 currently supports up to 300 Mbit/s of download speeds which is still short of the IMT-Advanced standards [32].Table 2.1 shows the data Speeds of LTE Advanced while fig 2.1 shows the Long Term Evolution (LTE) 4G MODEM.
Table 2.1: Data Speeds of LTE Advanced
CHAPTER THREE
METHODOLOGY AND SYSTEM ANALYSIS
Methodology
This work starts its investigation with the drive test facility of NCC in Abuja for data collection while comparing the QoS data with NCC reference dataset.This chapter will provide an insight into network performance management and quality of service (QoS) of GSM operators network. The methodology adopted identifies the components of QoS and the available mechanisms to analyze and evaluate them. This part also identifies important key performance indicators (KPIs) that need to be monitored and optimized and cites important data collected by protocols analyser in Air interface.
QUALITY VOICE MACHINE (QVM)
In configuration of calls for the measurement, intra-network call was made between master and slave channels of the QVM. This was done because it is always difficult to identify particular network that is responsible for failures in inter-network calls. Although additional testing equipment can be interfaced with response or collated data from the respective networks being monitored. But unfortunately network operators are likely would not allow an independent investigative monitoring of the interfaces between its network and another for comparison purposes.
ASCOM MOBILE TEST STRATEGY AND AMTS QoS SUPERVISION TECHNIQUE Ascom, a leading provider of Mission-Critical Communications, newly introduced Network Testing division.
CHAPTER FOUR
MNP MODELING USING FUZZY NETWORK
Mamdani Fuzzy Inference System for Network Integration
In this research, fuzzy Logic Toolbox was used in MATLAB Simulink environment to model and integrate different networks. After creating the fuzzy systems using the GUI tools, the FIS Editor displays general information about a fuzzy inference system. Using the Mamdani-type inference, as was defined for the Fuzzy Logic toolbox, this expects the output membership functions to be fuzzy sets. After the aggregation process, there is a fuzzy set for each output variable that needs defuzzification. Figure 4.1 shows the Mamdani-type inference framework used in this work.
CHAPTER FIVE
RESULTS AND DISCUSSION
Figures 5.1and 5.2 show the behaviour of the three networks, MTN, ETISALAT, GLO and AIRTEL in April, 2012.
CHAPTER SIX
CONCLUSION AND RECOMMENDATIONS
In this research, Key Performance Indices of network providers (KPI) which causes poor service quality in Nigeria were examined. The four network operators in Nigeria were analyzed in the context of their KPI data which NCC regulates. The application of drive test and deductive reasoning was exploited to show the non uniformity of the operators in terms of QoS delivery to its end customers. The review findings now lead to a novel method of subscriber migration in mobile cellular networks and its implementation framework in future mobile phones and devices. A novel QoS framework was presented which seeks to enforce expedite action on the part of the network operators for improved QoS demand.
An improved platform for MNP vis-à-vis Subscriber Identity Module (SIM) proposed by Trusted Computing Group Mobile Phone Work Group (TCG MPWG) Reference Architecture was developed and analysed. A Java VSIM portability Suite for Mobile Number Portability (MNP) parametric SIM network algorithm using fuzzy logic where implemented. The approach demonstrates the replacability of the existing MNP SIM card GSM architecture with an adequate trusted software module proposed to demonstrates the functionalities of the network integrations. Furthermore, the proposed method for SIM MNP (Mobile SIM Network Portability Suite- MSimNPS) for all mobile network operator and the migration of subscriber credentials between devices was analysed considering its integration techniques, and the parameters on which it depends. MSimNPS decision using fuzzy logic framework was developed showing the customer parameters while focusing its evaluation based on a set of benchmarks which are considered as crucial for deployment while taking cognizance of user’s requirements of mobile devices.
Contributions to Knowledge
Throughout this research, this work has made following contributions viz:
- Carried out an exhaustive literature survey on GSM QoS and KPI target analysis for possible improvements.
- Developed simplified QoS management framework for GSM operators in Nigeria
- Developed a fuzzy integrated GSM network for decision rule management, using Mamdani Inference engine.
- To develop a MNSuite showing the scenario migration processes for end users.
- Developed a GSM model for BER sensistivity with MATLAB Simulink.
Problems Encountered and Solutions
- The inability to locate a viable testbed environment to make preliminary investigations was a major constraint to this work. However, this was finally solved with the availability of simulation rich MATLAB Simulink which was used for the various implementations.
- Further, poor background on network softwares as well as simulation softwares was a big setback, but via the help of experts, researchers and other professionals, a light was shed in this direction.
Recommendations
This work recommends that the regulators must actively encourage the use of improved MNP scheme to avoid subscriber exploitation while compelling service providers to come up with innovative scheme that will improve QoS. Also, the concept of infrastructure sharing among the operators to reduce their cost of infrastructural deployment, maintenance, etc, allowing them to focus on QoS is highly recommended.
- The integration framework should be re-examined by the network regulator –NCC while seek possible interfacing considerations among the operators systems
- There should be an infrastructure sharing mechanism between the operators for cost reduction in CAPEX so as to improve on other areas.
- The NCC and the four GSM operators should increase efforts to educate Nigerian Subscribers on the Mobile Number Portability Scheme.
- Adequate information such as requirements, guidelines and turnaround time for switching GSM operators should be made public
- GSM operators should focus mainly on reducing their current rate of dropped calls, and also strive to improve the quality and coverage of data services, customer care and tarrif plan as these are identified as the highest sources of attraction by customers who want to switch to new networks
REFERENCES
- TCG Mobile Trusted Module Specification version 1.0, Revision 6, 26 June 2008.
- W.C Hardy, “Measurement & Evaluation of Telecommunications QoS” ISBN: 0-471-49957- 9 (hard back); 0-470-84591-0 (Electronics).
- J.D Vriendt et al.., “Mobile Network Evolution: A Revolution on the move” IEEE Communications, vol 40, No. 4, April 2002.Decision consult limited “GSM Quality of Service Evaluation survey: The Verdict”, published by Nigerian communications commission (NCC), 2007.
- [rGPP97a] 3rd Generation Partnership Project. 3GPP TS 02.09; Security Aspects. Technical Report 6.1.0, 3GPP, 1997. Technical Specification Group Services and SystemAspects.
- Http://www.en.wikipedia/MNP
- Gsm Service Providers Key Performance Indicators Comparison Mtn,Glo,Airtel,Etisalt Qos Kpi’s (January To November 2011)
- J.J Popoola, I.O Megbowon, V.S.A Adeloye, “Performance Evaluation & Improvement on Quality of Service of Global System for Mobile Communications in Nigeria” published by journal of information technology Impact vol.9, no.2, pp 91-106, 2009.
- B.M Kuboye, B.K Alese, O.Fajuyigbe, “Congestion Analysis on the Nigerian Global system for Mobile Communications (GSM) Network”- Pacific Journal of science and technology, 10(1):262-271
