There are myriad factors to consider when deciding on an in-building wireless solution. There’s performance, total cost, and ease-of-use issues to mull over. Do you want to use repeaters or small cells or voice over WiFi or a distributed antenna systems (DAS)? How many people do you need covered by the solution, and how many people does the system need to support simultaneously?
Once you decide on DAS, the decisions aren’t over. Another issue to add to the list: Whether to choose a high-power solution or a low-power one. The answer depends on a few factors, coverage and performance, cost and capacity, as well as future technologies. It’s important to understand your options before making a decision.
Zinwave’s Univity DAS is a low-power system, which, in our case, puts out about 100 milliwatts of power. High-power solutions, on the other hand, can be in the range of two watts, five watts or 20 watts at the radio frequency (RF) output. There are advantages to both, and again, there are multiple factors in play when determining the best use cases.
One of the most important aspects of every network is its signal-to-noise ratio. As network usage increases and users are requiring higher data rates to complete tasks quicker, this ratio becomes more important.
In a low-power system that doesn’t use coaxial cable, noise is usually higher than in high-power systems. However, in low-power system, signal loss is non-existent. The lack of coaxial cable allows for the signal from the user to maintain its intended strength. That’s not the case in high-power systems that use both coaxial and fiber cabling. This makes it much harder to balance the signal-to-noise ratio in a high-power network. What that means is that while downloading information will likely be unaffected, it’s going to be much harder to upload data to the network. And that includes voice calls which become data just like everything else once they reach the network.
When considering performance, it’s critical that future technologies and frequency demands be part of the consideration set. Unlicensed frequency spectrum in 3.5GHz to 4.2GHz will be very challenging or impossible to efficiently support using high-power networks. RF losses at those frequency bands over coaxial systems will be significant. Future technologies, specifically 5G, will require network latency be at a minimum. Coaxial cables used in high-power networks have higher latency than all fiber-optic networks used by low-power systems such as Zinwave’s.
High-power solutions require more equipment to be functional. This goes beyond the coaxial and fiber cabling. It also includes splitters and couplers. This added infrastructure increases the overall cost of a system and is why it is imperative to do a true apples-to-apples comparison when considering low- and high-power systems. While cost of direct DAS OEM components might be higher for low-power systems, cost of “non-DAS” materials as well as installation services will be higher for high-power systems.
Consider future needs
To determine the total cost of ownership, post deployment maintenance, operational costs and future upgradeability must be considered. A wideband, low-power system like Zinwave’s will require little to no upgrades for the future frequency bands, technology or operators. Consider the just completed 600MHz auction and what impact that will have to DAS upgrades. High-power systems will require new 600MHz modules, deployment of which will require another “truck roll” and costly additions to the passive networks that would cause degradation in performance of the existing services.
High-power systems will require a substantial amount of equipment to be installed in telco closets, where low-power systems won’t. Space and power are at a premium at most venues, so DAS operational costs (both in terms of power needs and operational expenses related to the amount of space occupied) will typically be much higher for high-power systems.
Monitoring costs should also be considered. In low-power systems, one can monitor the entire network, all the way to the antennas. In high-power systems, most of the time, the passive parts of the system (anything after IDF closets) isn’t monitored. Once troubleshooting is required, field crews have to make educated guesses as to where the problem with the passive distribution is, sometimes spending countless hours doing so; while in a low-power system, monitoring software will identify the exact point of failure within seconds.
Another element to think about is sectorization, something especially important for higher capacity solutions. In a large public venue, like a stadium, arena, convention center or airport with a significant numbers of users, a DAS system has to support more sectors, or zones, than in a a more contained installation, like in an office building. This is easier to achieve with a low-power system as each remote covers a much smaller/more granular area than a high-power solution and allows for a much higher sectorization on day one or in the future as capacity needs require.
This is becoming more important even for the systems that are coverage driven at installation. It’s much easier to efficiently scale for capacity a low power system, where each remote covers a much smaller area, as coverage needs shift. With a high-power system, where each remote unit covers a much larger area, you risk having too many people within that zone to be supported by a single network sector. That means the reliable cellular connectivity you were trying to provide may not be significantly better than it was before.
Consider Our Changing Usage Habits
In the end, the decision between low-power or high-power systems comes down to performance, total cost of ownership and future needs (technology, capacity, frequency bands).
Low-power systems will continue gaining market share as data usage and future technologies, like 5G and IoT, drive network capacity needs to new levels. High-power systems will continue to exist, either as a complement to low-power systems (think about a high-capacity venue surrounded by a low-capacity garage requiring basic coverage) or standalone solutions where today’s and tomorrow’s needs are limited to coverage only and capacity isn’t an issue (think a warehouse). So some companies may want high performance, a lot of capacity and good data throughput metrics. For venues requiring higher capacity today or in the future (and there should be more and more of them as the cell phone has become the communication tool of choice for the modern American worker), a low-powered solution will deliver the best performance.
The workplace is going mobile, and businesses are going to have to be able to create reliable cellular connectivity in their buildings to enable employees to use the devices with which they’re most comfortable and drive productivity. Knowing whether you need a low-power or a high-power system is a crucial part of choosing the proper solution.
Three things need to be considered when determining the total cost of ownership of a DAS solution. Learn more about them in our ebook.