In the first two parts of this series, we talked about Wi-Fi telephony, its promises and its pitfalls. The third part addressed enterprise-mobile integration. If campus dead spots are a problem, then another alternative is to undertake some in-building signal improvement. This is something that an IT department can do without going the full route of an enterprise-mobile integration, and it's something that any organization should consider if mobile usage is rising and on-campus cellular performance is falling.
There are several key points to consider when evaluating an in-building wireless solution. The first is: Who will do the RF engineering? Next up is the question of the cabling required and the available infrastructure. The question of a "passive" or an "active" architecture is also important. Finally, once the costs are added up, who's going to pay for an in-building solution?
Wireless networks operate within the radiofrequency (RF) spectrum, and any in-building solution is going to involve a fair amount of RF engineering and capacity planning. Modern cellular networks rely on frequencies between 850 and 1900 MHz, and remembering high school physics, the higher the frequency, the shorter the wave. And short waves have a tough time getting through anything solid like walls and concrete. For the same reason that AM radio signals travel thousands of miles, cellular telephone calls have a tough time making it into office buildings and big-box retail stores.
The question about RF engineering is how much of it you want to do yourself. A growing number of integrators provide this service, and this is one thing best left to specialists. Many RF design contracts will include network tuning and operational improvement "check-ups." These ongoing services are important because RF networks are organic, and your network will change with traffic, usage and anything that happens nearby. In other words, plan (and budget) to re-visit the RF component of your network on a regular basis.
The biggest fallacy about wireless networking is that it gets rid of cabling. Any IT manager will tell you that the Wi-Fi network uses quite a bit of the cabling infrastructure, and an in-building wireless solution will do the same. Since we're dealing with RF, the cabling is not always CAT5. More likely than not, thick coaxial cable that looks like a big gray serpent is present in the data center.
The familiar issues with cabling are the cost of running it, the complexity of bend radii, and the overall engineering required to figure out where it will go. When evaluating alternatives, ask first about cabling, because the available infrastructure may rule out some vendors or products.
Passive or active?
Other key factors for passive or active in-building systems are expansion and management capabilities. As we have already learned with wireless, it's virtually impossible to have enough capacity and enough coverage. Unless you know that you will absolutely never have to upgrade or expand your in-building system, plan on doing otherwise.
How many carriers?
If your company is going to invest in an in-building solution, will it support multiple carriers? A system that can support multiple operators will give your purchasing managers far better control when the time comes to negotiate the next wireless contract. Also, even if all of your workers are on a single carrier, a system that supports multiple carriers will provide improved signal performance for onsite partners, suppliers and service technicians who use other wireless carriers.
Some companies try to do an in-building solution on the cheap, relying on their wireless operator to make the investment. The rationale is that the company is "spending a lot of money" every month with the carrier and the in-building investment is "the least they can do."
This is troublesome for a couple of reasons. The first is that the carrier is already getting your money, so this is far lower on its list of priorities. The differing priorities carry through from design to deployment, and the carrier is apt to give you a solution that fits its needs, not yours. There's nothing wrong with this, but it's something to consider.
The most satisfied IT departments are the ones that make their own investments in an in-building wireless solution. That way, IT management can oversee the design and installation of the solution, and it can be a solution that supports multiple carriers.
Final word on in-building wireless
If your workers are using their mobile telephones in the office, and dropped calls and network dead spots are becoming problematic, it's best to consider an in-building wireless solution to improve the performance of carrier networks on campus. The in-building investment should be the first consideration, ahead of Wi-Fi and enterprise-mobile integration.
Next month, we'll put some evaluation criteria around the alternatives we've discussed so far: Wi-Fi telephony, enterprise-mobile integration, and in-building wireless. And we'll discuss the situations where it makes sense either to invest in Wi-Fi telephony or go beyond an in-building solution to include enterprise-mobile integration.