Illuminating The Invisible Broadband

Pushing fast access to the edge of the Net with satellite

To Internet service providers (ISPs) and infrastructure players, three consumer and enterprise markets are practically invisible.

Areas outside the major urban markets where high-bandwidth terrestrial lines are impractical or expensive; international markets seeking backbone access; and existing access providers seeking additional bandwidth without major investment timelines or costs go virtually unnoticed.

Illuminating these markets isn’t a matter of adding more ground lines. It’s a matter of using satellite-based systems with fast protocols and smart caching systems that push content and access to the edge of the Internet faster. Satellite-backed networks can be deployed more rapidly than terrestrial lines at a fraction of the cost.

It’s called the invisible broadband.

Connecting earth and sky

Working and living within a well-wired major U.S. market makes it easy to forget about areas that don’t have high-speed Internet access. Many ISPs serving such areas struggle to provide adequate access to customers.

India, a market with more than one billion people and a burgeoning technology sector, will be waiting for years to gala access to high-capacity terrestrial services. Even in the United States, access providers in major markets struggle to balance demand, costs and long construction time for extra capacity.

Building T1, D53 or larger connections for these markets, however, is not necessarily the answer. The most important factor is often decentralizing content. The goal is to push content as close to the ultimate user as possible — the edge of the Net.

The solution to this conundrum of fast access without terrestrial comes with the combined power of next-generation satellite transmission systems and community caching networks.

One of the biggest technical challenges with satellite systems is that of latency: delays in network response because of the distance satellite-based systems must transmit data, compounded by the milliseconds required to translate, route and compress data. Satellite-based systems using TCP/IP protocols suffer from inherent latency problems because of a combination of physics and the Internet standardization to TCP/IP. TCP/IP-based satellite systems introduce latency primarily because of inefficient methods to compress data — also known as packets–which form larger messages or files. Under these conditions, performance plummets with delays that can exceed 700 milliseconds, including round-trip signal transmission and packet delays.

Forward error correction codes add data redundancy to the transmitted data bit stream. The added redundancy allows the receiving system to identify and correct transmission errors. The data redundancy adds spectral bandwidth to the signal but allows reduction of power levels and often transmitter costs. In extreme cases, the transmitted power level can be reduced by as much as 90 percent at the expense of using more than twice the satellite bandwidth required by an uncoded signal. Use of forward error correction dramatically reduces secondary transmission requests and often contributes to lower hardware costs.

The combination of enhanced protocols, data compression and forward error correction lead to significant improvements in the encapsulation and un-encapsulation process, which determines the manner in which data is transmitted and received. Yet this combination is just part of the satellite-based “invisible” broadband solution, which differs from “visible” broadband of land lines.

The final frontier

A vital component to building invisible broadband and pushing fast access to the edge of the Net is dynamic, n-tier caching. Even with fast VSAT (Very Small Aperture Terminal)-based satellite transmissions, the greatest efficiency of invisible broadband comes from placing caching systems at each downlink site. Caching systems are a form of high-speed, temporary storage for data that needs to be rapidly available.

The true power of such caching systems comes from the ways they are grouped and regionally managed. Local caching systems connect both to the network’s core parent cache systems and to each other. In a given area, several local caching systems will share and dynamically balance the most popular content to serve a region faster and more efficiently as an n-tier network. An n-tier network is a generic description the new-generation of client-server systems that have many more layers or clusters of networks than the two-tier client-server model. N-tier networks more closely resemble the way the Internet really works – a network of networks and add greater capacity to distribute information to a wide number of users.

A combination of prioritization protocols and pre-emptive caching algorithms determine storage of popular content such as Web pages or video files. This n-tier, dynamically balanced system forms a community caching network (CCN).

The general premise of VSAT-based caching networks is that data is easier to push to the perimeter of the Internet than to manage high-volume requests that distort bandwidth requirements. To this end, pre-emptive caching maximizes low usage time periods to replicate potentially entire Web sites or networks.

Satellites connected to dynamic caching systems benefit regional groups of ISPs as well as individual ISPs. When a request for a given piece of Web content is made, the reply from the parent cache is multicast to the entire caching community at once. Multicasting ensures that cumbersome redundant requests are reduced.

For individual users, the architectural upgrades translate to faster access, but commercial-caliber clients benefit as well. For firms concerned about security and dedicated bandwidth, the invisible broadband model forms a virtual private network (VPN), which spares concerns about exposing data and mission-critical applications to the public Internet. These same VPNs can be extended to completely private networks for dedicated applications.

The above scenarios and example are most appropriate for areas outside major urban markets or international ISPs seeking a gateway to the Internet backbone. Yet one of the greatest opportunities for invisible broadband is to augment the capabilities of ISPs in major markets seeking to improve the speed and diversity of services without the major investments required for additional land lines.

Savvy ISPs and content aggregation

In a business where success depends on maximizing efficiency and volume of traffic on razor-thin margins, ISPs in major markets must constantly seek opportunities to cut costs while maintaining excellent service. But frequently, the only option to expand bandwidth is the addition of DS3 or other high-capacity lines, which often take too much time to build and fail to lower operational costs.

The VSAT-based satellite and caching structure provides the optimum solution to this problem by offering a way to build an overlay network with a quick set-up in a matter of weeks and much lower operating costs. Yet, the key to success isn’t just about fast access, but savvy content aggregation. ISPs in major markets can deliver the best of the Net to customers without delays by prioritizing the most popular content.

In addition to the CCN, there are several forms of content aggregation and distribution that enable the multi-tiered invisible broadband network to operate smoothly. Pushing Internet services close to the end users is necessary to reduce non-customer traffic over a satellite hop.

First, DNS (Domain Name Servers)-to-IP conversions are cached locally, which saves time that domain name servers usually need to convert names to numbers. Second, ISP customers can set up their own email structure under POP3 (Post Office Protocol) and SMTP (Simple Mail Transport Protocol) to include virus protection and distribution that put remote servers closer to end users.

Third, content aggregation operates in both directions, bringing the most valuable content to the edge of the Net, but also hosting remote applications, such e-commerce servers, in target markets. This type of Web accelerator is similar to a proxy server, but in reverse — bringing content and applications closer to the targeted audience.

Fourth, security is a very important aggregation service for schools or municipalities. To protect customers from hackers who take advantage of remote networks, satellite-based broadband networks provide additional firewall support.

In concert, these services augment an ISP’s offerings while providing a buffer zone of bandwidth for usage spikes driven by streaming media, voice over IP (VoIP) and other bandwidth-intensive applications. With dynamic load balancing of service and data types, ISPs gain bandwidth control and monitoring.

Over the horizon

As ISPs migrate from a purely terrestrial-based infrastructure model to a hybrid approach with satellites and caching, future services loom as opportunities to expand offerings to customers.

Distribution support for ISPs serving their customers as content aggregators means that multiple POPs can receive content and applications with a single satellite transmission. This reliable and cost-effective management technique ensures that customers always have the fastest access to information.

Replication services that re-distribute information among multiple users will equip providers of bandwidth-intensive applications with more reliable delivery to end-users. By transferring bandwidth-intensive applications to multiple locations, reliability of service increases with minimal concurrent bandwidth requirements.

The Internet access marketplace has tremendous growth opportunities. But the need for cost-effective, fast access requires a new model, especially for areas outside major markets, outside and inside major U.S. markets where low-cost bandwidth augmentation is imperative. VSAT-based satellite systems with high-speed protocols and savvy caching systems bring all the elements of success together in a single, time-tested package.

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