Dynamic Data Delivery

Getting the most out of your data network isn't just about optimization; it's also knowing how to use it.

Data is eight times more bandwidth-intensive than voice and isn't as forgiving of certain levels of signal degradation, so optimizing your networks for data is critical.

“You have a scarce set of resources, and the problem is data is a bit more consumptive of those resources,” said Jeff Miller, Agilent Technologies (www.agilent.com) functional manager, wireless network test division. “The optimization problem is going to be more difficult as the percentage of data users increases.”

Data traffic bursts for significant periods of time and is always on the uplink or downlink. These characteristics create difficult RF problems, which also stem from pushing more energy into a finite amount of spectrum.

Optimization technologies are critical to filling the gap between the network's capabilities and the user's expectations, according to Glen Stancil, BlueKite (www.bluekite.com) co-founder & vice president of product strategy.

“Today, most of the data services that are provided on networks are very simple, like SMS or WAP,” he said. “As operators move to more complex services, in particular services rooted in HTTP and all of its derivatives, to access the broader Internet with devices equipped with color, fonts and rich-media capability, the expectation grows dramatically.”

Most carriers optimize their networks today, but if you're not optimizing correctly, data performance suffers. Some solution providers say compression is the best way to optimize; others suggest adding caching, as well.

Optimization Imperative

Optimization can help prepare data networks for 2.5G and 3G services by boosting spectral efficiency, i.e., capacity and throughput. If you optimize your network for Internet traffic, you don't need to do it again when 3G rolls out; although, you will have to upgrade when moving from HTTP 1.1 to HTTP 2.0.

“This is a forever business of trying to get the most out of a limited amount of bandwidth,” said Bob Smith, Fourelle Systems president & CTO (www.fourelle.com).

Picking an optimization strategy — compression, caching or a combination — depends on subscriber needs, current network configuration and other factors.

Today's optimization solutions include BlueKite's Data Reduxion and optimization platform, Fourelle Systems' Venturi platform, mDiversity's (www.mdiversity.com) software solution and Speedwise's Accellence technology (www.speedwise.com).

Through caching and compression algorithms that reduce unnecessary data transmissions over wireless networks, BlueKite's software solution optimizes and increases speeds for wirelessly accessing Web content. Users can browse the Web via a wireless connection at five times normal speed while using eight times less bandwidth (average).

Fourelle Systems' Venturi solution speeds up data transfer with content-specific compression and transmission solutions that reduce Internet data sent and received. An optimized protocol maximizes narrow bandwidth, sending 50% to 90% less data across the network with no apparent loss to the user. Fourelle converts TCP protocols to a reliable UDP transport to enhance compression and speed.

“We actually look at the protocol,” Smith said. “We compress HTML differently than we compress the image on that Web page and differently than we compress a .doc file attachment.”

When you apply compression, however, you must apply it appropriately because different kinds of compression affect a network differently.

“In all cases, the effect is to take the data load off of the network, but you should be careful how you do that, and it should always be based on the type of data being sent,” Smith said.

Data reduction is critical to the success of next-generation, IP-based networks such as GPRS and WCDMA, where data-packet volume directly affects network performance. Speed-wise's Accellence boosts the wireless Internet experience so users can browse the Web up to six times faster, without installing client-side software. Accellence ultimately increases a network's virtual bandwidth by reducing the volume of data the end-user receives in a browsing session. The technology delivers wireless browsing at speeds up to six times faster than currently available average rates.

MDiversity's multilink networking software solution decreases the mobile transmit power by as much as 75% and increases the capacity and data throughput by more than 100%, said Naveen Dhar, mDiversity vice president of marketing and business development. Installed at the base-station-subsystem level, mDiversity's technology increases network performance by enabling the mobile to communicate with more than one base station during a connection and optimizing the radio signal.

“In data, we can use the same efficiency rates to transmit at higher data rates,” Dhar said. “You can use it to reduce the amount of spectrum for voice, or because you have a stronger link, you can transmit at a higher data rate and put more users on the system.”

Although compression seems to be the most widely used solution, carriers also may add caching capabilities to their optimization arsenals.

With caching, you pack the data before transmitting it over the wireless interface to get as much information into the bandwidth as possible.

“It's a way of optimizing the service, but it's more of a network strategy when you work with handset suppliers and the server itself to reduce the amount of bits you have to push over the RF interface,” Miller said.

The result is a better user experience, so caching probably should be part of any good optimization strategy.

Optimizing Service Plans

Optimization provides new pricing options, allowing carriers to charge based on optimized data usage.

Carriers might charge an extra $5 a month for optimization, but it will save users $30 a month in bandwidth costs plus result in a better experience, and they will promote it that way, Stancil said.

“Alternatively, (carriers) can just include it in the network, especially if the value is accruing directly to the operator. If it's a fixed pricing plan, they'll just include it de facto and not do any sort of tiered-pricing,” he said.

Although optimization can distinguish carriers' service plans, carriers aren't taking advantage of this yet.

“They apply all of the compression, all of the time, for everyone,” Smith said. “At 14.4, it's so bad that even the base subscribers need all the help they can get. Carriers, to their credit, are doing the best job they can for every single user.”

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How's Your Data Performance?

Determining the performance of your data network isn't easy. In fact, according to Jeff Miller, Agilent Technologies (www.agilent.com) functional manager, wireless network test division, understanding the IP as well as the RF network side is downright complicated.

“The challenge will be collecting data from the various infrastructure components to understand what its performance looks like, as well as being able to collect data from the RF side of things to understand what impact that's having on the end-to-end performance,” he said.

According to Miller, automatic frequency planning or other types of RF propagation modeling can help, as well as having those solutions available and being able to model changes before you make them. However, carriers today have little experience with packet-based wireless network services.

“We have to be careful about how we represent high-bit-rate, always-on-type services to customers and understand what the implications of those are in terms of capacity, RF planning and infrastructure,” he said. “If you look at 2G cellular, it took three, four, five years for people to develop the right types of operational policies and practices to manage, maintain and optimize the networks. I see packet-data IP services falling into that same line.”