Improving Call-Completion Rates

You are well aware that the battle for new subscribers has never been hotter. Increased competition, new digital technologies, enhanced services, creative billing programs and increased churn rates have intensified the fight. Now more than ever you need to concentrate efforts on keeping your hard-won customers happy with their service.

Because your subscribers, by and large, don't understand the technical jargon related to wireless services, they tend to judge the performance of your network at a very simple level -- their ability to successfully place and end a call. Because of the way wireless services are marketed, customers have come to expect no difference in the performance of a wireless service compared with that of fixed-line service. About the only problem they will tolerate when placing a call is a busy tone from the called party, and even then not all the time.

Unfortunately, reality does not always match expectations when it comes to wireless, which results in customers complaining about poor performance of the service. They eventually will churn if the perceived bad performance continues. It is your job to see that your customers are able to place calls satisfactorily and hang up in their own time, regardless of the technical reasons for call-completion problems.

A range of factors can result in a customer's failing to complete a call satisfactorily.

Although the percentages below will vary from network to network, they are a fair indication of the breakdown of call-completion problems facing you and your subscribers:

* Handoff problems/dropped calls (29%) -- Incorrect neighbor lists, incorrect network handoff parameters, settings or hysteresis resulting in dropped calls

* Interference/quality (25%) -- Co-channel or adjacent channel or from external sources

* Lack of capacity/blocking (22%) -- Lack of capacity channels, trunks or resources, particularly at peak traffic times, blocking access to the network

* Absence of RF (15%) -- Caused by poor coverage, shadowing, no in-building coverage or network equipment failure

* Phone or subscriber problems (9%) -- Poorly performing subscriber units, damaged or out of specification; poorly educated customers using handsets incorrectly by not raising antennas, choosing ill-advised locations to attempt calls or trying to place calls while outside advertised network coverage boundaries.

It is good network management to know in advance of your customers the problems they may find when using your network. You also should have the ability to check quickly on reported problems. You can monitor the network problems above via regular network audits or technical reviews.

Drive Testing A network-audit regime includes actual coverage analysis, which you can determine by drive testing essential areas of your operational network, as well as new cell sites and those areas that have changed after optimization work, using high-performance RF scanners. You can use these results to determine areas of poor coverage and also to calibrate planning tools to gain more accurate predictions of coverage.

Remember to take into account degraded performance of portable phones used inside vehicles. You also should carry out coverage testing for in-building service, as subscribers expect to be able to use portable phones anywhere.

Drive testing also can collect underlying network engineering data automatically from subscriber phones in conjunction with RF scanners. This will help you find the causes of problems such as highlighting with neighbor lists, handoff parameters and potential adjacent and co-channel interference problems. You can conduct more detailed analysis of likely interference areas with specialized RF tools to show sources of third-party or co-channel interference.

You also can use drive testing effectively to simulate actual subscriber use by using subscriber phones with automated dialing patterns. By doing so, you can exercise your network and collect statistics on instances of dropped, blocked and no-service calls. This higher level of metrics can shorten a review process dramatically by directing engineering effort at highlighted problem areas without the need to wade through all the engineering data. This way, you can concentrate your effort only on problem areas.

Drive testing, combined with statistics collected from the switch, will give you a complete picture of how your network is performing. It can identify potential "hot spots," or areas in which lack of capacity is causing problems.

This, coupled with audits of frequency and channel assignments, will help keep down churn by pro-actively ensuring that subscribers can access the system when they need to and don't suffer network-terminated calls.

Over-Performance is Issue The above work is labor intensive and time consuming. But the results can be used not only to find areas of under-performance, but also to identify potential areas of over-performance. Too much capacity is as expensive as too little. Reducing a planned roll-out or optimization by one cell site can go a long way to funding the test equipment and effort required for monitoring network performance.

After the testing and results come the actions to cure problems and improve performance. Good and plentiful information can give rise to a number of solutions, which do not necessarily need to be engineering related. Customers complain only when their expectations are not met. Better education both in marketing and sales can help promote realistic subscriber expectations. Using a product correctly with enough knowledge about its limitations and ways to overcome those limitations can help your customers avoid being disappointed in the service you deliver.

In addition, an approval-testing program on products available for subscribers to use on your networks can forewarn your managers of problems with a product that does not meet industry specifications.

Within your network infrastructure, reviewing installations before they are included in the network plan will allow you to catch simple problems such as antennas connected to the wrong feeder or incorrect downtilt. Simple errors like this can affect coverage and handoff performance severely as well as mislead engineers as they differ dramatically from predicted performance.

Reviewing the data you have collected from switch and drive tests is important to ensure that your handoff parameters are set efficiently. An increasing number of parameters are available for "tweaking" performance, but without a baseline of data, you face the danger of incorrect or excessive changes being made. You also run the risk of changing settings instead of curing core RF problems. Neighbor lists incorrectly configured always figure highly in handoff problems, especially when you neglect to change lists following optimization work. Incorrect neighbor lists directly affect traffic management, which ensures that mobile stations are directed at the correct neighbor, thus managing traffic load and reducing dropped calls or calls being bounced back and forth needlessly between cell sites.

Correct Network Settings Ensuring correct network parameter settings also can go a long way in avoiding the need to add resources, such as extra channels or additional sites. But with very high traffic areas or bad coverage areas, you may have no choice but to do so. In particular, adding pico cells to solve in-building or hot-spot problems is an effective solution. But it also introduces the new problem of ensuring proper containment of coverage so that problems such as interference to adjacent cells or creation of a new hot spot are not added.

Because your subscribers are continually monitoring successful call completion, you need to do the same, viewing call-completion rates as an essential indicator by which to judge your network performance. The most effective way to manage and improve call-completion rates is by the regular collection and review of drive-test and switch-statistic data, which are key components of network audits. Only by the collection of data can you locate problems and provide solutions.

Available solutions to individual problems are numerous and vary with the network technology in use, so you will not be able to find one magic cure to improving completion rates. What you will find on the market are better methods of finding solutions. Your ultimate goal is to make your subscribers' expectations reality while making your network as efficient as possible.