Welcome to the first in what I hope you will find to be an interesting series of monthly columns. In each installment I’ll share my perspectives on the evolution of broadband services, and in particular, the future of VoIP. I will examine the ways in which changing technologies, as well as changing business, political and regulatory environments, influence broadband service providers and their customers.

 

Today I will look at the ways in which changes to silicon technology are helping address changes in the political and regulatory environment, specifically, how those technology changes are dealing with the issue of power consumption in residential VoIP gateways. We’ll also examine how these changes have the added benefit of yielding cost savings, which hopefully will be passed on to the consumer.

 

However, before I get into the details, it’s time for a brief introduction. I’ve been involved in the VoIP industry since early 1997. I started a new job as business development manager at Texas Instruments (News - Alert) and my boss asked me to take a look at the voice over Frame Relay market. At the time I had no idea what Frame Relay was, let alone what voice was doing ‘over’ it, but it was clear that, even back then, TI was selling quite a few DSP chips to manufacturers of voice gateways. It quickly became apparent that we were at the beginning of a telecom revolution driven by a transition to all kinds of packet voice transport, especially voice over IP, in all parts of the network. Since then, I have developed a passion for this industry and market as my career took me to another system on a chip vendor (Broadcom), an embedded VoIP software vendor (D2 Technologies (News - Alert)) and now a provider of voice interface circuits, (Zarlink). Now, back to the subject at hand.

 

Recently, I’ve been thinking more frequently about the power consumption of residential VoIP gateways. You may ask why anyone would care so much about this. Basically there are three reasons - battery life during power outages, cost and the environment.

 

Battery life may be the most obvious reason to be concerned about power consumption. Many broadband and VoIP service providers, especially the cable companies and Fiber to The Home (FTTH) providers, such as Verizon (News - Alert), include a Li-Ion back-up battery in their residential gateways. In the event of a localized power outage affecting the customer’s home, the battery in the gateway will maintain both broadband and VoIP service for several hours, assuming there is still power at the network ‘head end’, and assuming that the customer has an old fashioned line powered phone (i.e. not a cordless phone that requires wall power). Clearly, reducing the power consumption of the residential gateway increases the time that it can operate from the battery; typical requirements are five hours talk time, eight hours standby time. A residential gateway vendor might want to reduce power consumption to increase the time the gateway can operate on a battery, or to allow a lower capacity battery to maintain the same back-up operation as would have required a larger batter. Being able to use a smaller battery means lower cost.

 

The battery is usually the most expensive single component in a residential gateway, so reducing power consumption can result in significant capital cost savings for a service provider (and maybe increased profit for the residential gateway vendor). If a service provider can reduce capital costs, the time to payback on their investment in capital equipment is reduced. Alternatively, a service provider can reduce the monthly rates they charge their customers, and still enjoy the same payback period, making their service more competitive at a new lower monthly price. However, a residential gateway does not have to be battery backed-up to realize cost benefits from reduced power consumption. Lowering power consumption can mean that a less expensive external A/C wall power adaptor can be used. Lower power consumption also means lower power dissipation and less heating in the residential gateway, meaning cost can be saved on heat sinks etc., and maybe a less expensive enclosure can be used.

 

Finally, let’s consider the environmental impact of reducing power consumption. Although individually each gateway only consumes a few watts, if you aggregate all users, the power consumption of residential gateways is significant, especially since residential gateways are always powered on. This concern has led the European Commission to create a voluntary code of conduct specifically defining recommended maximum power consumption for various types of broadband gateways. To illustrate the benefits of saving just a fraction of a Watt in each gateway, let me walk you through a quick “back of the envelope” calculation. Essential in any residential VoIP gateway are the telephone interface circuits, or SLICs and SLACs that connect to the telephone jacks in the gateway. Today, many residential gateways use chips that typically consume about 300mW of power when the phone is on-hook. Even more power is consumed when the phone is off hook or ringing, but lets just look at the on-hook state because that is the state the gateway will be in most of the time. (Except for the gateway in my mother’s house, that it is more often in the off hook state!!!) However today new SLIC/SLAC chips are available that reduced this on-hook power consumption to less than 100mW, a 200mW saving for each phone line. Consider the positive impact that reduction can have in the case of a large VoIP service provider, with say, five million VoIP customers (similar to France Telecom (News - Alert)). If each of these VoIP customers has a two line residential gateway, and the service provider upgrades each customer to gateways using the new SLIC/SLAC chips, the power savings are 400mW per customer, or 2 MegaWatts total. That’s the equivalent of the power consumed by approximately 1,000 European homes.

 

So, you can see that seemingly small power savings at the individual level can add up to significant power savings at the macro level, and taking advantage of the latest silicon technology is not only good for the environment, but it also reduces costs, benefiting the planet and the balance sheet.

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Rick Bye (News - Alert) is a senior segment marketing manager with Zarlink and is responsible for leading the company’s residential gateway and consumer voice products development.