Current access technologies overview

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White Paper

Current access technologies overview

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2 Digital subscriber line – how much longer?

Digital subscriber line is the most mature of these technologies in terms of its early acceptance, standardization and use. This family of technologies (including ADSL2+, VDSL, VDSL2) provides Internet access by transmitting digital data over a local telephone network. Basic DSL requires fiber build-out to a node, or terminal, which is close to the customer. From the node, a twisted-pair copper connection is made to the existing copper within the customer premises.

Advantages

• Cost per subscriber typically low compared to most competing technologies, • Leverages copper in existing homes

• Approximately 80% of brownfield builds in the world have twisted-pair copper in them • Ability to provide broadband service over the existing copper infrastructure – and not spend

additional money Disadvantages

• To provide greater bandwidth, nodes must be moved further into the field and even closer to the customer

• Reduction in coverage area since distances are shortened as bandwidth increases • Requires power in the outside plant where electronic equipment resides

• Electronic equipment in the OSP makes the network potentially vulnerable to natural disasters, such as floods

Ultimately, DSL will reach the point where it can no longer provide enough bandwidth to enough customers – thus, a major technology upgrade will be required.

DOCSIS – positioned to compete

DOCSIS (“data over cable service interface specification”) is an international telecommunications standard used by many cable television operators to provide high-speed data or Internet services over existing hybrid fiber-coaxial (HFC) infrastructures. Similar to the DSL, fiber is run to a node where the signal is transferred from the fiber to coaxial cable and extended to the customer in a direct line to the home.

Advantages

• Coaxial cable better shielded than twisted-pair copper, making it a much better medium for data transmission

• With release of a Gigabit standard for DOCSIS, this technology meets present-day bandwidth requirements

• In some parts of the world, it is less susceptible to damage from natural disasters, as nodes are located above ground on power poles

Disadvantages

• Power source required within the outside plant

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G.fast – new kid on the copper block

G.fast is a new access technology being developed to extend the life of copper beyond a Gigabit. This technology targets brownfield deployments as a fiber alternative that reuses existing copper infrastructure in homes and other buildings.

Advantages

• An alternative to the higher cost and slower rollout of fiber in brownfield scenarios • Reuse of existing copper infrastructure

• Relatively quick rollout • Rapid return on investment Disadvantages

• Distances are limited; G.fast equipment must reside close to the end user to produce a Gigabit of bandwidth.

• Reliance on reverse power feeding requires power from end user’s terminal to G.fast interface

• Crosstalk affects performance; without vectoring noise cancellation, G.fast rates are severely degraded

• Does not use frequency division duplex (FDD), but rather time division duplex (TDD) utilizing different time slots for upstream and downstream transmission. Transmission speed of 1 Gbps typically refers to the sum of both upstream and downstream bandwidths

Still, if G.fast can achieve Gigabit speed, it can meet bandwidth requirements in homes for the next four or five years and provide an upgrade path to FTTH. This makes G.fast a viable technology for service providers seeking higher bandwidth delivery in brownfield situations.

Satellite – no infrastructure necessary

Although not always grouped among popular telecom technologies, satellite does provide a medium for video and data transmission as a direct competitor to cable television operators. Advantages

• Cover wide areas without the need for infrastructure

• Provide services to remote areas under served or not served at all by other media Disadvantages

• High initial input cost of either launching a new satellite or leasing use of existing one • Upstream and downstream transmissions are not equal – downloads are typically

faster than uploads

• Transmissions are vulnerable to weather conditions and other failures that can cause service outages for long periods of time

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4 Wireless – still needs fiber

Wireless technologies provide extensive coverage to many people and devices. While any wireless network requires fiber (wired) backhaul, once the customer is in a home or office, wireless connectivity is typically switched to a wireline technology. Although an increasingly critical part of consumers’ daily lives, wireless can be viewed as more of an “add-on” technology to a service provider’s overall fiber network.

One major difference between a wireless and a fiber-to-the-home/node/etc. network is that there is never a one-to-one ratio of user to provider. Instead of having a dedicated line between the customer and the node, multiple wireless users simply tap into the wireless network and extract bandwidth.

Since wireless antennas are not unlimited in bandwidth, too many users can cause service availability and quality issues. To alleviate congestion, wireless providers deploy more antennas requiring power and fiber connectivity. Thus, providing higher bandwidth necessitates either more antennas or a reduction in the coverage areas.

Optical fiber – bandwidth unlimited

Optical fiber is still superior in its ability to deliver limitless bandwidth. Once the service provider deploys optical fiber, bandwidth capacity is likely sufficient for the next hundred years. This makes fiber the best choice for greenfield applications, but also a huge consideration in many brownfield situations where current technologies are approaching bandwidth limitations. Advantages

• No power requirement between the central office and the end user

• Virtually “limitless” bandwidth potential; only capped by architecture chosen and that architecture’s ability to migrate to newer optical technologies

• Optimal flexibility • High reliability

• Easy migration path for equipment and technology upgrades • Longer network life

Disadvantages

• Higher costs associated with brownfield deployment • Longer roll-out times

• Expensive labor costs • Slower returns on investment

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CommScope

(NASDAQ: COMM) helps companies around the world design, build and manage their wired and wireless networks. Our network infrastructure solutions help customers increase bandwidth; maximize existing capacity; improve network performance and availability; increase energy efficiency; and simplify technology migration. You will find our solutions in the largest buildings, venues and outdoor spaces; in data centers and buildings of all shapes, sizes and complexity; at wireless cell sites and in cable headends; and in airports, trains, and tunnels. Vital networks around the world run on CommScope solutions.

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