Reaching Maturity

Your engineering department has completed its initial design. You have finished the first round of optimization and satisfied primary coverage objectives. You've covered most of the major roads, taken care of the important business centers and serviced the main residential areas. If you look at the big map on the wall, you don't see any coverage holes. You can sit back and relax, right? Wrong.

System planning is an ongoing process, and as your network matures, you will face many additional challenges in RF design and site selection. How your established system adapts to the competitive landscape can mean the difference between long-term success and network failure.

Data Makes the Difference

Regardless of its size and development stage, there are four primary factors for designing and deploying a wireless system: capacity, cost, coverage and quality. Although each carrier will prioritize and weigh these factors differently, all service providers must address each of these fundamentals for a successful network.

Data is the critical component to meeting basic planning needs. The most important difference in RF design and optimization for a mature system is that the process no longer is based on engineering and marketing assumptions. Planners have to analyze and make decisions based on actual data.

Instead of employing the necessary tools and database-management techniques to process and use this valuable information efficiently, many operators use only a small percentage. Often, this is because the operator's current tools can't filter and pinpoint the data it needs easily.

Generally, initial systems are created from predicted data using propagation-modeling software tools. This approach is time- and cost-efficient, because the tool does most of the work. Propagation modeling can provide a good indication of coverage for a new system. But mature systems require a more accurate picture that reflects the reality of urban build-out and seasonal changes. Only measured data can provide this detailed information.

The increased availability of measured data, including drive-test performance data, usage data from the switch, customer-service reports and billing information, enables RF engineers to improve service through detailed system optimization.

Multilayer mapping and analysis software tools allow you to analyze and display almost any type of database information on top of geographic data, providing nearly unlimited multiple layering functions from internal and external sources. This capability allows engineers and marketers to share information across departmental lines and make full use of all databases. These tools are a necessity, not an option, in today's high-volume data environment.

Switch data is a key part of system planning. Although initial designs rely on projections from marketing data such as demographics, once a system is operational, projections are not enough. You need switch data, which provides a true representation of the system's traffic flow. It shows congestion problems on individual cells, indicating lack of capacity or low usage, and therefore an inefficient use of network resources.

For efficient and productive system planning, you can use switch-data-display software tools, which allow you to filter through mountains of data quickly. Being able to query and capture traffic information efficiently improves the entire planning process.

Mature systems also rely on switch data for coverage plans. During initial development, overall funding determined the number of cells you built and the initial coverage area. But for a mature network, you have to track and evaluate each base station separately so that you know the profitability of individual cell sites based on traffic, revenues, and build-out and maintenance spending.

Coverage objectives also become more defined as increased traffic and new services put more demands on the network. As your system grows, subscriber usage patterns change, and traffic planning moves beyond providing basic mobility. The objectives become more specific. Not only do you have to cover a 10-mile stretch of interstate, but also the 6-building corporate complex four miles off that interstate.

When you are placing a site to ensure complete in-building coverage for a high-use area such as a business park, that site may have only a 1- or 1/2-mile radius. You must know exactly where customers are, which site the traffic is going to, and when it's flowing. You can get all of this data from the switch.

Throughout the life of your network, you will track quality issues with network-based data. Accepted measurement levels such as grade of service and signal thresholds determine quality objectives for new systems. Once mature, switch data and additional drive-test measurements give you a view of qual ity issues for the entire network and for individual cells. Indicators such as handoff performance and dropped calls provide an accurate customer perception of system quality. As capacity increases, quality becomes a key priority -- and challenge -- to maintain a high level of service.

Site Selection

As you continue network expansion, you will likely run into site-acquisition challenges as well, even more so than during initial build-out. Unlike mature system deployments, the search areas for new systems are larger, and although coverage objectives are specific, they are flexible. This flexibility allows you to identify multiple sites in the search ring and, in some cases, outside the original search area. But site acquisition for mature systems provides considerably less flexibility.

First, network maturity leads to RF difficulties. RF objectives are aligned to provide signal in specific geographic areas and are bound by inflexible design parameters. This leads to extremely small search areas, with some mature systems requiring locations to be within only 100 feet, or even 50 feet, from the center of the issued search ring. This could eliminate a rooftop if only one corner of the building is available and, in many cases, may leave only one suitable site that meets RF objectives.

In early development, it was rather easy to shift and move base stations as needed. With multiple sites available, you could select a site for best coverage, lease rate, ease of regulatory compliance and reasonable civil construction costs. But as your network matures, so does the market. More carriers are entering the market and following the same development patterns as their predecessors, using the optimum sites. Unless the local municipality has a strong co-location policy, all priority locations could be taken.

Markets with substantial growth also house residents opposed to tower proliferation. As a result, new ordinances and moratoriums are adopted to address these concerns.

Today's site owners also are becoming more skillful and experienced in the acquisition and negotiation process and in understanding how each search area fits into the RF plan. Sophisticated site owners result in more extensive and expensive negotiations.

To minimize the long-term financial burden of acquiring sites under these circumstances, it is important to use personnel who are highly efficient in lease negotiations and resolving municipal regulatory compliance.

Another option is to change methodologies. For example, you could team RF engineers with deployment personnel early in the design process. Working in tandem, deployment professionals can communicate critical information such as approximate building heights and zoning restrictions to RF engineers more easily. RF engineers can use this information for design and deployment parameters to determine new-site placement, streamlining the entire site-design-and-acquisition process.

Your site-acquisition specialist must have a clear vision of the RF objectives before investigating the search area so he doesn't waste time and resources exploring non-productive sites. It is imperative that all involved in the deployment process understand the siting possibilities in their markets. It is never cost-effective to plan for expansion into an area that will not permit the application or into one that requires more time and money than allocated.

Building Solutions

Although there are many challenges in planning expanded systems, there are some inherent benefits of maturity, specifically in construction. In most cases, civil construction materials providers are established and material logistics are in place. Site-construction standards have been instituted, and a portfolio of tried-and-tested civil contractors is available.

But construction is more than assembling site components into a cohesive, functioning unit. In many ways, this discipline is more involved with the deployment process than any other. Once search rings are issued, itis vital at each step in the process that construction personnel assess all site candidates continually.

When you decide a location is critical to the system, it is up to the deployment team, particularly the construction personnel, to provide the most cost-effective solution that meets jurisdictional/ownership requirements. It is imperative that construction personnel understand RF objectives in order to facilitate those requirements.

The ongoing development of a mature network always is a challenge. No matter how much planning has gone into the initial design, growth always will demand adjustments. There is no time to sit back and relax, because how effectively your network adapts will decide whether your system ever really reaches its golden years.