Quality of Service in the Nigerian Telecoms Space

Hi, It is my intention to do a series on the inefficient communication networks we have in Nigeria and I welcome comments on this.It is over eight years now since the introduction of GSM and other mobile network services in Nigeria, given birth to a number of operators in the industry.While NCC has been largely successful in selling communication licenses to would be operators and existing ones, it has not met with equal success in regulating these kinds and quality of networks being rolled out in Nigeria. This have subjected the industry to a number of speculations, bad and poorly designed networks and equipment flooding the market with the attendant poor quality of services from all the operators , leaving the subscribers to the mercies of these operators whose only goal is profit, profit and moor profit.In these series I will like to pursue the causes of these poor qualities of services in the Nigerian telecom industry and perhaps proffer some solution to these problems. While some of these issues are very technical, it is my desire to simplify the language so that the average reader will understand to some degree the issues involved in delivering a quality network.The mobile or cellular network can be rightly divided into three areas: Namely,

• The access network


• The Core Network


• The management Network

Each and every one of these segment can and does contribute to poor services that the user experiences in the Nigerian telecom industry today and I will try to explain in a layman’s language what this segment stands for and how each one contributes to poor network quality. Let me say here that the Nigerian telecom market is characterized up till now with, poor grade of service, poor call completion rate, poor service delivery, charging problems and poor customer service units. Each and every one of this brings with it the irritation experienced by subscribers. Unfortunately, no network is immune from these ills presently. All appears to be in the same cup of tea with varying degrees, the PTO’s inclusive. Lets us discuss the network segments.

The Access Network

The access network is the access point to the network by the network user or the subscriber. On the network side, It is comprised of the base station which is installed within the mask area that you see littered on our streets and high ways, The Base station Controller which is the switch that controls all the base stations in an area. On the user side you have the handset and the SIM card. This is fairly the same for all networks for now at least. The base station receives request from the mobile handset to either set up a call or send an SMS etc. The base station under the control of the controller (Base Station Controller) will either allocate a channel of communication between the mobile handset and the network or refuse this request based on certain conditions prevalent on the network.The refusal of service request to the handset is in almost all cases in the Nigerian scenario based on inadequate radio resources or channels. This refusal of request impacts greatly on the grade of service of the network (GOS). Usually during planning the grade of service of a network is chosen between 2% to 5%. This is the internationally accepted standard. Though there are exceptions. For instance ETISALAT, the new entrant plans its network on 1% GOS which is really very high and probably if realized will be unmatched in the Nigerian market. By the way The GOS simply represent the number of refused calls in every 100 calls. So if I make 100 calls and only 80 out of that is successful, then the GOS of the network is 20%. In the case of ETISALAT for instance they planned that for every 100 calls you make, 99 will be successful. Ahah!!! what on earth happened to them. Realizing an acceptable grade of service requires effective planning and efficient allocation of network resources where it is needed. In Nigeria today, particularly at busy hour the average grade of service is 20% and in some networks as bad as 50% and this is obviously unacceptable. These problems could be solved simply by keeping to an acceptable levels of GOS. Which means that operators cannot take in more subscribers in a particular area or region than what they have the capacity to absorb. I will leave technical details that deal with channels and channel allocation to a mobile handset behind as this will simply bore the average reader. This segment has been the one NCC has concentrated so much energy on, by monitory radio quality using drive test and other quality monitoring equipment. Rightly though, as this constitute 70% of user perception of quality in any giving network.

The Core Network

The core network is the switch that connects your call from one subscriber to another either in the same network or on differing networks. It is simply an interconnected web of digital computers designed to do this kind of job. In a mobile network, the BSC is connected to the core network or the switching system through voice channels and signaling links. The voice channels carries the voice data while the signaling channels or links carries the information exchange between the various computers that enables them to setup a call or to tear down (release ) one. Connection between one switch and another is also similar to this kind of connection between the BSC and the switch.Congestion and refusal of service can occur in this segment . Therefore if there are inadequate voice channels between switches (Transmission problems), overload on the computer CPU’s due to oversubscription or bad planning, inadequate exchange link between switches or between BSC and a switch, then poor quality of service is inevitable.

Transmission

At the onset of GSM and PTO services, the operators complained that NITEL is not providing enough transmission facility for their traffic (E1). This resulted in the operators building their own transmission network resulting in the defacing of our landscape across the country in the name of laying fiber optic networks. Today almost every operator has its own transmission network whether by fiber or radio, but these problems still persist to some degree though varying from network to network. So transmission facility alone is not the reason for poor network quality in Nigeria.

CPU Overload

In my humble opinion, this is the singular most offensive cause of poor network quality in Nigeria and I will try to dive into this in a little bit more detail. Remember that the switches are merely a distributed form of computers doing the work of routing calls from one point to the other. In fact they are not much more different from your laptop computers and desktop PCs. They actually use the same chips at their core. Most of them uses even less processors as can be found in the present day laptops or PCs. While most laptops or desktop computers are running on probably Pentium 4 or Centrino dual core processor from INTEL, most switch CPU’s are running on Pentium 3 or Pentium 2 with either 128MB,256MB or 512MB of RAM memory. So in terms of architecture, they are the same with some minor differences though. The life and load of this CPU’s are central to the performance of any network. Every CPU comes with a baseline load. This is the load that the CPU carries when there is no traffic on it. This load value is a good indication of how well the switch vendor has designed its product. A typical baseline value maybe 5% to 7% range. A 10% baseline load would be rather high. Obviously a higher baseline load means that less processor capacity is available to the application environment. A processor cannot operate at 100% capacity for a number of reasons. First, as a processor reaches its maximum operating level it begins to shed tasks assigned to it for processing. These tasks are prioritized with regard to the operation of the switch. For instance, the administrative operational task of switching may be given greater priority than the actual call processing tasks. This design is sometimes used by the manufacturer to assure that the switch does not encounter catastrophic failure whereby all communication and control of that node are lost. The BSC also has a CPU for its operation since it is just a “radio switch” as a matter of fact. For a BSC CPU, acceptable traffic load levels should not exceed 50% for most manufacturers if it does, the CPU will begin to lose a lot of paging request (and may restart) resulting in many “subscriber unavailable error” even when your handset is fully powered on and you are looking at service. Yet the network says you are not available. This is caused by an overload of the BSC CPU resulting in delays in processing paging request from the Main switch. In Nigeria it is not uncommon to see CPU load levels of 70% and above, and this is a major source of poor network quality and performance. CPU overload on the switch itself comes with a number of problems, they may include: Denial of service, Faulty connections Faulty call releases Cross talk( a common situation where a caller is connected to someone different from the one he is calling) Dropped calls and many others Typically traffic loads on the switch should not exceed 70% by all standard. This is not the case in Nigeria where most networks switches operate at 90% CPU load and even more. Ideally the processor load should remain on average around 40 to 45% so that at busy hour, when traffic should be nearing double the average hour it should not exceed 70%. Operators simply load their networks and do not care much about the attendant service quality. To underscore this point, If you have a laptop or a desktop computer running windows XP for instance you can always check out for the load on your CPU. By just pressing down ctl alt del at the same time, then click the task manager tab and then performance tab.You will notice the fluctuation in your CPU load. If it nears or exceeds 70% its performance will deteriorate badly and it will probably become unstable and wacky. You may then begin to look for an anti-Virus probably to help restore normalcy on your computer, because something is eating up the CPU power. This is not different from what happens to a switch CPU when in overload condition.This condition should be monitored by NCC on these operator’s equipment; and notorious vendors and operators alike should be sanctioned. There seem to be a deliberate attempt to cheat the Nigerian people on these poor services. I am of the opinion that these poor services are not as a result of vandalism or power problems as it is being alleged. It is purely coming from poorly planned and poorly managed networks designed to exploit and not to render effective service. There are poor power situations in GHANA, same in Sierra Leone. I have been privileged to be involved in network roll outs in these other countries and they enjoy far better services than we do. I will continue this series by looking at the side of the network that deals with billing, charging and recharging at a later date which I called the Management Network Segment.