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Inconsistent services and quality of the mobile networks

By Augustine Odinma

The quality of mobile operators’ services since 2001 when they rolled out in Nigeria has been a hotly contested issue. We have seen from a recent published research, that the networks are still very congested after a decade that it became commercially available. Moreover, the quality provided by each operator is inconsistent from one city to the other.

The error messages sent to telephone users are incongruent with the real problem. The issuing of SIM Cards and its registration has continued to be a major cause of concern for users. In this paper we look at the variability in services of operators across cities. We also look at some of the error messages and the bottleneck introduced by SIM Card registration in some cities. The primary research under my supervision was carried out by six of my students from American University of Nigeria: Jude Okwuibe and Ridwan Naibi for Abuja; Joshua Shawulu and Emmanuel Chukwudozie for Lagos; and Khadija Masanawa and Iniabasi Udobong for Yola.

Inconsistent operators’ service and quality

We used two metrics to examine the quality of services of a particular operator in various cities. Specifically, we chose Lagos, Abuja and Yola. We wanted to find out the behaviour of operators between big metropolitan cities on the one hand and a representative small metropolitan city, such as Yola, on the other.

We used intra-connectivity and inter-connectivity percentage failures metrics to carry out the test. The intra-connectivity measures the internal congestion of a particular base station subsystem and the inter-connectivity measures the ability of one operator to interconnect with another. The sites chosen for the test are such that a percentage failure of more than one per cent would be considered a statistically congested network.

Figure 1 shows call failures from one AIRTEL, MTN, GLO and ETISALAT networks’ subscribers to another in the same network, respectively. Using the intra-connectivity test, we observe from the figure that for Abuja, we have a maximum percentage failure of 4.2% and for Lagos, a maximum of 5.2% across all the operators. However, for Yola, we observe for MTN, GLO and ETISALAT between 10% and 27.5% failures.

This observation for Yola is a remarkable difference from those observed for Lagos and Abuja. This high value represents a very high level of congestions in the networks, but more particularly, it shows that users in the smaller cities enjoy lesser quality of services than those in the bigger cities across operators. This really should not be so because all customers get charged the same amount for calls made. It is important that the industry regulator, NCC, monitors such inconsistencies in the quality of service from each operator.

When we examined the inter-connectivity metric (Figure 2), we made similar observation as we did for using the intra-connectivity metric. We find that for the one unusual case of AIRTEL to MTN, which we consider as statistical outlier, Yola yielded the highest percentage failures in each case. This clearly shows that mobile users in Yola find it much more difficult to interconnect with other operators. In layman’s terms, they would have to make several calls on average to be able to connect other networks as opposed to users in Lagos and Abuja.

Announced or displayed error messages

There are several error messages observed during the course of our research. These are error messages either displayed or announced to subscribers when they try to make calls. Most of the announced or displayed error messages are not a true representative of the real cause of the problem. We shall analyse some of the announcements or displayed messages below and thereafter, make some observations. As you read these messages it is important that you keep in mind that the calls were made between two phones in the same test room and thus registered with operators’ Base Station Subsystems, where there is full signal. So, this test scenario is one that should be error-free. Find below some of the error messages:

MTN error messages

1. Sorry, your call cannot be completed at the moment.

2. Sorry, your account is too low. Please load all in one card.

3. No circuit is available.

4. Sorry, the MTN number you are calling is not reachable at the moment.

5. The number you are calling is not available at the moment.

6. Error in connection.

GLO error messages

1. The number you are calling is currently switched off or out of coverage.

2. The number you are calling is incorrect.

3. Error in connection.

4. Sorry, your account is too low. Your call cannot be completed, please recharge your account.

5. This number does not exist on the GLO mobile network.

6. This number does not have the facility to receive calls.

AIRTEL error messages

1. The number you are calling is currently switched off.

2. All lines in this route are busy.

3. The user is busy on some other call, please try after sometime.

4. Error in connection.

5. Network busy.

Etisalat error messages

1. The subscriber is currently not available.

2. Number busy.

3. Error in network connection.

4. The number is out of network coverage.

VISAFONE error messages

1. The subscriber is busy on some other call.

2. Your call is restricted.

3. The subscriber cannot receive calls at the moment.

As earlier observed, in most cases these error messages do not correspond or represent the true cause of the network problem. This leads one to infer that the wrong messages displayed or announced are masking the real problems in most of our networks. It is possible that for some of the operators, some of the wrong messages are inadvertent. However, it is obvious that most of the wrong error messages could be an attempt to conceal the real problem, and this is unethical, unprofessional and fraudulent. Let us take for example, MTN’s error messages (1), (2), (3), (4) and (5). Why should these errors occur when we have a test scenario that should be fault free? Error 1 says “Your call cannot be completed at the moment.” Why not, given the test scenario? It seems the correct message should have been “our network is congested at the moment!” Furthermore, Error 3, which says that no circuit is available, identify that there is an equipment problem, but the bottom line is that the network is congested. Moreover, Error 4, which says: “Sorry, the MTN number you are calling is not reachable at the moment”, is one that is really worrying because you are looking at the phone you are calling and it has full signal. Again the problem would only be congestion in the network. As for MTN Error 2, “Sorry, your account is too low. Please load all in one card”; it is ridiculous because the phone had more than N500 in credit.

These problems are not peculiar to MTN. Some of the other operators are even worse in some respects. Let us examine GLO error messages (1), (2), (4), (5) and (6). GLO Error message 1, says “that the number you are calling is currently switched off or out of coverage.” But this is not true. The phone is registered with the same network and has full signal. The same is the case for GLO Error 2, “the number you are calling is incorrect”, whereas the number is correct. Again, GLO Error 4, which says: “Sorry, your account is too low.

Your call cannot be completed, please recharge your account”, is ridiculous because there was a credit of over N500. Moreover, GLO Errors 5 and 6 are just mere camouflage. GLO used to have an error couple of years back, which would say “Call rejected” when it is not true, but we found that this error is no more displayed or announced to their credit. Similarly, AIRTEL error messages 1 and 3; ETISALAT error messages (1) and (4); and VISAFONE error messages (1), (2) and (3) are fallacious messages.

It is the contention of the author that majority of these error messages mentioned above are symptomatic problems of congestion in the networks. This is primarily because the operators’ network systems are overloaded with call requests. It is obvious that if a particular operator happens to be announcing congestion always, it could lead to loss of customer to others. But it is seriously unethical to make announcements that are misleading. It is therefore important that NCC should get the operators to behave responsibly in this aspect by sending the appropriate error messages.

SIM Card Proliferation and Registration

The SIM Card registration, while it is plausible, has also added another dimension to the suffering of mobile users in the smaller cities, such as Yola. We bought SIM Cards from MTN, GLO, AIRTEL, ETISALAT, and VISAFONE eight (8) days prior to the date we planned to start research. There was no VISAFONE in use in Yola, so we could not test its service there. A truly national operator should have presence in at least each state capital after over about four years it gained its licence; otherwise, it should not ordinarily qualify to be a National Operator. The registration of VISAFONE SIM Cards was relatively easy in Lagos; the SIM Cards were activated within hours.

However, in Abuja the registration we made for VISAFONE was never activated, even as I write. ETISALAT told us that the registration would be completed within two hours, but it took about eight hours for the SIM Cards to be activated. GLO told us that before the day runs out, the SIM cards we registered would have been fully activated, but it became ready the following day.

The MTN office in Yola told us that it would take two weeks for their network to activate the SIM Cards because of poor network link. The young man carrying out the services further said that sometimes he had to stay late to upload the registration he made. We pleaded with him to help us upload our phones faster. After five days we went to him to expedite action, but our SIM Cards were still not activated after two additional days.

We had to travel to MTN office in Abuja and got the phone cards activated within hours. We could not have the AIRTEL SIM Cards activated in Yola after seven days that we had gone to register in the AIRTEL agents’ office. We took the SIM Cards to Abuja and registered them anew and the activation took a day. So, we could not register the MTN and AIRTEL numbers in Yola after 7 days, but it took hours to have it done in Abuja and Lagos. This shows the variability of operators’ services from one bigger city to a smaller one.

In order to register a SIM Card in a smaller city, mobile customers may have to pay a bribe, otherwise, the agents may not upload their registration in order to facilitate activation of SIM Cards. This is unacceptable and NCC would have to work with operators in order to remove this additional layer of suffering for mobile users from Yola or other smaller cities.

Finally, our research shows that the GSM networks are heavily congested. We have used a scenario that should have no call failures to test the networks, but our test results do not just show accidental congestion, but enormous percentage failures.

This is primarily due to the fact that operators proliferate SIM Cards production without making sure that the infrastructure can cope with the number of issued or sold SIM cards. In advanced countries, where this level of congestion may occur, the operators are checked by the fact that the savvy users would avoid the operator’s service. In Nigeria, where users have no genuine choice or quality conscious operators, the NCC ought to save the users from such exploitation.


This paper presented some of the outcomes from a recent research conducted to study the behaviour of five mobile operators in Nigeria. Over 70,000 calls were made during the six days of the studies in order to ascertain the reliability of the networks. The study examined different times of the day and different days of the week in order to capture the peculiar behavioural pattern of users.

The study took place in Lagos, Abuja and Yola. Research sites were chosen in each city, where all the operators consistently have full signal. The sites were also chosen such that there should be no fault at all during the course of the research. So, any percentage call failure of more than one per cent represents serious congestions of the network. Any network that is congested in this test scenario would pose a serious problem to rural areas and calls between two distant users.

The intra-network and inter-network connectivity were major metrics used to evaluate the networks services. We not only found that the networks were heavily congested, but we found that for each operator, services are inconsistent from one city to another. The mobile users in smaller cities suffer from congestion than the subscriber in bigger cities for each operator. All mobile users are charged the same tariff, but the ones from the smaller cities do not get as good service as those from the bigger cities and this is not fair. The NCC should work with the operators to check this variable service across cities.

There are clear cases of exploitation by the operators. The registration of SIM Cards has introduced another layer of suffering for mobile users from smaller cities. The registration and activation of SIM cards for MTN and AIRTEL took beyond seven days in Yola. This has led to some level of corruption on the part of their agents’ employee, who expect some gratification before they would upload the registration request to head office.

We are also concerned about the proliferation of the SIM Cards by the operators, which are not adequately backed with proper infrastructure. Moreover, the failure messages given by operators are incongruent with the real cause of the failure. A case in point are operators messages, which says “The number you are calling is currently switched off”, when the phone is still on; or the one that says “number busy”, when it is not, etc. It is the contention of the author that if the current level of congestion in the mobile networks and variability in services across cities are not checked and arrested, it would have far-reaching consequences for the future of mobile services in the country.

lOdinma is Professor of Telecommunications and IT, American University of Nigeria, Yola, and was formerly Head of Network Solutions (Europe, Middle East & Africa), Lucent Technologies (Bell Labs), and also former Senior Technical Manager, AT&T, NJ, USA.


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