Corning Optical breaks down the various wireless power solutions
As in-building wireless usage continues to grow, building owners must find ways to meet the cellular coverage and capacity needs – both today and tomorrow – for their employees, tenants, guests, patients or fans. Regardless of the technologies used, owners will want to consider high-, medium- and low-transmit power solutions – or even a combination of them. The challenge is choosing the best power option for a given venue’s unique and evolving requirements.
A few years ago this choice was simpler. In the early 2000s, most networks were just shifting to 2G digital systems focused on voice. With capacity being less of a factor, high-power systems could blast signal throughout a venue to provide adequate cellular coverage. More recently, as wireless data demand exponentially grew and 3G and LTE networks were deployed, the right power solution had a range of answers depending on the venue. And with LTE-Advanced and “5G” network deployments on the horizon, the equation is changing again. These technologies are driving active components to the edge to be integrated with the antenna.
High-, medium- and low-transmit power distributed antenna system offerings are very different in terms of capabilities, performance and potential drawbacks. Understanding their differences and their fit with different building topologies and future network requirements can help building owners in their selection.
Door No. 1: the case for high power
High-power wireless solutions offer many benefits. Their primary benefit is providing in-building cellular coverage for an economical cost per square foot – typically in venues with large open areas or uniform floor plans. High-power remotes have larger coverage areas so fewer remotes are needed and require less overall space in telecommunications closets.
Still, there are drawbacks. High-power solutions, which typically drive large passive coaxial cable and antenna networks, are inflexible. System upgrades, such as adding multiple-input/multiple-out, can require major recabling. They also do not match well with future envisioned network architectures with distributed actives at the edge. High-power systems are best suited to lower user density and low sector counts. Each remote can cover a larger area, but requires substantially more electrical power – typically 800-plus watts. The larger remote coverage areas equate to less granular monitoring performance and less effective localization services such as E911.
What it’s best for: low density user environments such as large open areas, parking lots and more uniform high-rise buildings with static requirements.
Door No. 2: the case for medium power
Many deployments are not clearly suited for either high- or low-power solutions and may need something in the middle. Facilities with a mixed topology, such as a hotel with guest rooms on upper floors and ballrooms on lower floors, may benefit from a more mid-range coverage and capacity per remote.
Medium-power solutions have greater flexibility than their high-power siblings. They provide cost-effective cellular coverage and capacity that often better matches less uniform venue styles. They can accommodate higher sector counts for denser user environments yet deliver enough power for large indoor spaces. More remotes are required, but each takes up less space and consumes less electrical power, typically up to 400 watts. These systems provide better granularity for system monitoring and localization as each remote covers a smaller coverage area.
On the down side, medium-power solutions are challenged in that system upgrades, such as MIMO, can require major recabling. They also do not match well with future envisioned network architectures with distributed actives at the edge.
What it’s best for: semi-dense user environments with mixed topologies such as airports, shopping malls, hotels/convention centers and college atriums/quads.
Door No. 3: the case for low power
Low-power solutions have a growing place in the network. With more granularity per remote, they work well in high user density applications, which require more RF “contouring” and support higher sector counts, to provide additional cellular capacity for a given venue. They provide better visibility into network performance – all the way to the edge – and more accurate end-user localization. Facilities also enjoy better uplink performance from device to network. Each remote is smaller and uses less electrical power – typically well under 100 watts. Unlike high- and medium-power solutions, which rely on hybrid fiber-coax designs, low-power solutions add all-fiber based options. These match well with future network architectures envisioning cloud radio access network delivered via fat fiber pipes to distributed active antennas at the edge. They also enable economical converged solutions where multiple applications (cellular, POL, and Ethernet backhaul for Wi-Fi or femtocells) can run over a common infrastructure.
The tradeoffs are the reverse of the benefits of their high-power cousins. Low-power solutions have a higher remote density because each remote has a smaller coverage area. This also means more overall space is required for the remotes; however, this does not necessarily mean more telecommunications closet space as low-power remotes may be mounted closer to the edge of the network. Low-power solutions can be more expensive per square foot particularly if cellular-only coverage, and not capacity or bandwidth, is the primary design factor.
What it’s best for: dense user environments, including stadiums, high rises, shopping malls, college campuses, hotels, hospitals and airports.
Got different needs? Try a mix of solutions
Finally, when it comes to determining which solution is best, some facilities may benefit from a combination. For example, an arena may need a low-power solution to support a high-sector count inside the venue and a high-power solution to accommodate adjacent large parking areas.
At the end of the day, building owners have different power level solutions to choose from to address their in-building cellular coverage and capacity needs. If owners consider not only traditional factors, such as building topology and user density, but also how the network will change over the life of the building, such as upgrades, cellular network evolution and how network applications may merge, this will go a long way to help them pick the solution that is “just right” for their needs.
Editor’s Note: In an attempt to broaden our interaction with our readers we have created this Reader Forum for those with something meaningful to say to the wireless industry. We want to keep this as open as possible, but we maintain some editorial control to keep it free of commercials or attacks. Please send along submissions for this section to our editors at: [email protected].
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