IN-BUILDING WIRELESS BEST PRACTICES

CHAPTER 5

To learn more, visit commscope.com2

The opportunities of using DAS and small cells

Meet the diverse family of IBW technologiesThe phrase “in-building wireless” is a catchall term that covers an entire class of diverse, specialized solutions that require enterprise owners, managers and architects to carefully weigh the benefits and costs to determine the most efficient solution. It’s imperative that the ideal solution meets not only the needs of today’s tenants and users, but also offers the flexibility and agility to serve future needs as well.

This chapter will look at two of the most significant classes of IBW solutions: distributed antenna systems (DAS) and small cells. While they share some physical and configuration similarities, they operate differently. Each offers unique advantages.

DAS: powerful and scalable coverage for large venuesBuilt from a networked series of remote antennas, or nodes, DAS is one of the industry’s longest-established wireless coverage and capacity technologies. DAS is an effective means of delivering uniformly high quality of service (QoS) wireless coverage and robust capacity across:

• A large indoor area (such as high-rise office building)

• A contiguous outdoor area (such as a stadium, open courtyard or entry space)

• A combination of indoor and outdoor environments (such as a college campus)

As mentioned in Chapter 2, indoor areas are covered by low-power DAS, and outdoor spaces are covered by high-power DAS. The latest generation of DAS solutions can integrate both low- and high-power networks into a single, unified platform for mixed environments.

DAS is an inherently scalable solution, which means it can be expanded to cover larger spaces and awkwardly-shaped areas. For example, when cellular service is added to a subway tunnel, a sprawling sports arena or a tunneled mountain road, chances are that it’s being done with DAS.

The physical infrastructure of DAS generally relies on RF cable (i.e., coaxial cable) to link antenna remotes. It uses fiber-optic cable to connect various floors or other discrete areas. Both types of cable then connect to a central processing point, called the headend. Some more advanced DAS solutions now operate on IT structured cabling instead of coaxial, making it easier to install. IT cable also supports other networks and functions, like Wi-Fi, security systems and so forth; its broad use means that installers are relatively easy to find and inexpensive to hire.

IBW fast factsDAS deployments provide reliable coverage and capacity in environments that other solutions can’t handle.

One example is the Perot Museum in Dallas, Texas. 14 stories tall and covering 180,000 square feet of display space, it features CommScope solutions to power integrated video displays, VoIP, security systems and much more.

To learn more, visit commscope.com 3

It’s worth noting that DAS is just that—a system of distributed antennas. It connects to the operator’s network through that operator’s own base station, which allows DAS to work with one, many or all available wireless operators in the market. New operators can connect to the existing DAS infrastructure for instant access to high-quality, high-capacity coverage.

Each DAS installation is unique to the environment it serves, so there are no out-of-the-box DAS solutions—though there are innovate new options that simplify the process with intelligence-enabled automatic configuration (Figure 1) and alternative means of signal transport, such as via an existing IT cabling infrastructure (Figure 2).

CENTRALOFFICE

RESIDENTIAL/MDU

OUTSIDEPLANT

MICROWAVEBACKHAUL

INTELLIGENTBUILDING

SMALLCELL

DATACENTER

FIBER TOTHE HOME

OUTDOORCELL SITE

ION-E: Unified Wireless Infrastructure

CAN MM/SM FiberCat 6A

UAP

WiFi

IP CameraTEN

IBW fast factsDAS is a suitable IBW solution for:

• High-rise office buildings

• Large hospitals and hotels

• College campuses

• Shopping malls and museums

• Stadiums and sports complexes

Figure 1: An intelligent auto-configuration of outdoor DAS optimizes coverage and capacity in a large stadium.

Figure 2: An IT-converged DAS infrastructure uses network cabling instead of expensive coaxial cabling.

These factors make DAS an attractive option for large venues, mixed indoor/outdoor venues, isolated locations and spaces where demand is variable, but has the potential to be extremely high. In these cases, DAS makes financial sense.

As far as DAS has come since its early days as a niche solution, it’s not always an economical solution for smaller enterprise environments, though recent innovations like IT-convergent solutions that operate on network cable are lowering the cost of entry.

To learn more, visit commscope.com4

Small cells: affordable and adaptiveFor smaller indoor locations, small cells offer an economical alternative that’s flexible and self-contained. Small cells are what their name implies: small versions of macro cell sites, including base station, radio and antennas, typically combined into a single physical unit. Small cells are able to support deployments spanning the size of a small-to-medium office building, where demand levels are relatively consistent from one day to the next, distribution of users does not vary to any great extent, and demand is not expected to spike to extreme levels.

Each small cell creates a discrete “cell” of coverage. Like macro cell sites, traditional small cells also create areas of overlap where their cell boundaries meet. In these areas, cellular connections suffer significant drops in service quality: reduced data rates, choppy voice, and dropped connections. This problem can be mitigated through thoughtful design and careful optimization of small cell placement and power, but it’s impossible to eliminate this cross-sector interference entirely (until recently, that is—we will explore the latest small cell innovation in the next section).

Small cells are relatively easy to install, which makes them an attractive option for an enterprise environment. We will explore this in more detail in the next chapter.

Unlike DAS, which connects to an outside base station owned by a wireless operator, small cells include their own baseband unit, which must be integrated with operator networks—a one-time process. As of this writing, most major operators have only integrated a limited number of small cells and some have not integrated any. This situation is improving, but slowly. A given model of small cell typically only supports one operator’s network.

Also bear in mind that small cells have a hard upper limit of coverage and capacity that may present serious challenges if the IBW solutions will need to expand significantly in the future. Small cells can reliably support 16 to 64 users at a time, which may be more than adequate for many small to mid-sized enterprise environments. In addition, unlike DAS, conventional small cells cannot dynamically share capacity between access points, so large gatherings in small spaces may create bottlenecks—a phenomenon sometimes called the “cafeteria problem.”

C-RAN: the best of both worlds?We stated above that small cells suffer from the same cross-sector interference that sometimes plagues the macro cell network and that concentrations of users can overwhelm individual access points. In traditional small cell architecture, this is true. However, a recent innovation from CommScope has removed this barrier from small cell deployments, making them even more attractive for deployments of the right size. This innovative approach is called a cloud radio access network, or C-RAN small cell. Here’s how it works.

The base band unit centralizes all processing from the small cell’s various radio points, creating a virtual “super cell” that combines the entire system into a single area of coverage.

This eliminates QoS issues and dropped connections by eliminating overlap altogether (Figure 3).

As an extra bonus, this architecture operates over conventional Ethernet switches and cabling, making it easier to install and maintain without expensive or specialized expertise.

Single cell withno borders

CoordinatedRadio points

Baseband Controller

Switched Ethernetfronthaul

Device ManagementSystem (DMS)

Operator CoreNetwork

Figure 2: An IT-converged DAS infrastructure uses network cabling instead of expensive coaxial cabling.

To learn more, visit commscope.com 5

DAS or small cell? It depends on the job you need it to perform.Choosing a solution for an IBW deployment involves several questions. How much space must be covered? How many people must be supported? How much will the coverage and capacity demand change from one day to the next? And, perhaps most importantly, how much will it all cost?

DAS and small cells comprise the lion’s share of IBW solutions. They each have their place and purpose. By carefully identifying expectations—and thoughtfully considering the future of your business—the ideal IBW solution will become clear.

Keep in mind, however, that both DAS and small cell solutions continue to evolve and improve over time, with several key innovations hitting the market right now. Small cells are improving their scalability, and DAS is becoming more economical by the day.

This means that you—the owner, manager or architect—will have access to an ever-improving array of options as time goes on. However, this won’t be your only decision point; you will also want to consider the possibilities of using licensed versus unlicensed frequencies in your IBW solution, which we will discuss in the next chapter.

Chapter 5 summary• IBW encompasses several diverse

technologies

• DAS and small cell are two of the most promising alternatives

• DAS is ideal for larger, mixed venues with highly variable coverage and capacity requirements

• DAS is not always economical for smaller areas of coverage

• Small cells are suited to small-to-medium spaces with consistent demand

• Small cells offer similar benefits and drawbacks of the macro cell network

• C-RAN is a breakthrough small cell innovation that eliminates many of small cells’ QoS limitations

Everyone communicates. It’s the essence of the human experience. How we communicate is evolving. Technology is reshaping the way we live, learn and thrive. The epicenter of this transformation is the network—our passion. Our experts are rethinking the purpose, role and usage of networks to help our customers increase bandwidth, expand capacity, enhance efficiency, speed deployment and simplify migration. From remote cell sites to massive sports arenas, from busy airports to state-of- the-art data centers—we provide the essential expertise and vital infrastructure your business needs to succeed. The world’s most advanced networks rely on CommScope connectivity.

commscope.comVisit our website or contact your local CommScope representative for more information.

© 2017 CommScope, Inc. All rights reserved.

All trademarks identified by ® or ™ are registered trademarks or trademarks, respectively, of CommScope, Inc. CommScope is committed to the highest standards of business integrity and environmental sustainability, with a number of CommScope’s facilities across the globe certified in accordance with international standards, including ISO 9001, TL 9000, and ISO 14001. Further information regarding CommScope’s commitment can be found here.

CO-110744-EN (02/17)