VOIP IN THE MAINSTREAMBy Richard Evans, Segment Marketing Manager, Digital Enterprise Group, Intel Corporation
This article provides a brief overview of the status of voice over internet protocol (VoIP) in the home today, and discusses the prospects for growth over the next two years.
It is hard to argue with the reality of VoIP. Skype just celebrated its first birthday, along with nearly 150 million downloads. Vonage's advertising has helped to bring VoIP to the mainstream in the United States and according to a Vonage press release on May 5, 2005; the company has successfully raised over $400 million in investment capital.
What has made VoIP a reality today? First, the fast uptake of broadband access among consumers has created a critical mass of VoIP-capable end-users. Within the past three years (2003-2005), world-wide broadband (cable and DSL) subscribers have grown from 91 million to 175 million according to Infonetics . And, by 2008 the Infonectics forecast grows to 254 million subscribers. So, without a doubt the world-wide growth of broadband is enabling more efficient and rich IP services, including VoIP. Secondly, the availability of widely affordable and sufficiently powerful PCs, relative to ten years ago, has made personal computers available to larger numbers of people which has increased the technology astuteness of mainstream consumers. Additionally, technology has advanced to the point that the quality of VoIP service has reached virtual parity with traditional phone service which has resulted in non-phone company VoIP providers drawing significant numbers of subscribers away from traditional telephony providers.
There are several ways to take advantage of VoIP as a residential broadband consumer. One method is to use a software only application, running on a Windows* PC such as Skype. Alternatively, some VoIP providers, such as AT&T, provide the hardware platform and the user must also subscribe to a broadband service. A third way is to upgrade through an existing service provider, as many of them now offer additional services called `double play' (data, voice) and `triple play' (data, voice, video) to their subscribers. Usually, all that is necessary to add voice is to obtain the service provider provisioned hardware, which is typically a highly integrated residential gateway.
A popular hardware approach for VoIP in the home is the two-box model as shown in Figure 1. In this configuration, the residence has a broadband modem (cable or DSL) and some type of analog telephone adapter (ATA). Typically the ATA is integrated into the Ethernet router (which usually has several additional functions) which is connected to the modem. Depending on the service provider, the hardware is either provided directly, or the user independently purchases the appropriate modem and ATA-capable gateway.
Although there are the inevitable growing pains with technology advances such as VoIP, history shows that technology will continue to advance in order to meet consumer needs. For example, there has been much press on the lack of emergency 911 service for consumers who rely solely on VoIP. The FCC has required VoIP providers to create an E911 service where dispatchers can view a VoIP emergency caller's address. However, there are technical challenges since a user could physically relocate his VoIP equipment and connect anywhere in the IP network without notifying his service provider. In the short term, this issue is being addressed by having VoIP customers register their physical location and electronically sign a waiver.
Quality is much less of an issue today with VoIP than in the past given advancements in CODEC (coder/decoder) and Packet Loss concealment technology. However, there are still imperfections in service quality from time to time, such as audio delay and dropped calls. Most phone users in the United States and in most industrialized nations take reliable phone service for granted. It is always on, and rarely fails unless a phone line is damaged. Can VoIP service be regarded as equally reliable? What happens to VoIP service when the power goes out? Some Internet service providers (ISPs) also have reliability issues, so a home user is dependent on their ISP's reliability. For users to switch to VoIP, the quality of the voice call must be equal to or better than their current service. Today, the common CODEC is G.711 which provides a quality score (mean opinion score - MOS) of 4.1 (5 being the theoretical maximum). The wide bandwidth CODECs with their 7 KHz bandwidth and better dynamic range (about 45-50 dB) will help drive MOS up towards 5.0 and remove the shackles of the traditional time division multiplexed (TDM) 3.5 KHz experience.
In addition to quality expectations, there must also be a cost savings to increase demand for VoIP. One example of VoIP service in the United States is the AT&T CallVantage® Service. The AT&T Web site describes the CallVantage Service as providing many more features and at a much lower price point (savings as much as $250) than their current traditional phone service. AT&T advertises unlimited local and long distance calling, plus call waiting, caller ID, call forwarding, voicemail, locate me, do not disturb, and other features. A subscriber can keep their current phones, and combine VoIP with their current broadband service.
There are several hardware options available on the AT&T Web site. For example, many retail stores already carry the AT&T ready telephone adapters which integrate Ethernet routers, Wi-Fi* and other features. The AT&T products contain high performance, highly integrated processors such as the Intel® IXP425 network processor. These processors allow original equipment manufacturers (OEMs) to offer multi-function boxes at very attractive price points while providing the requisite call and voice quality that users expect. High performance processing is necessary to deliver high voice quality and security. Voice quality is dependant upon such considerations as the voice compression algorithm (CODEC) and priority of the voice packets. Security is critical for reliable service since VoIP enabled gateways are connected to the Internet which opens it to some risks.
Looking into 2006-2008, many more telephone, cellular and cable providers will be offering VoIP and other services to customers. And, many of the issues such as call quality, always-on reliability and emergency services dialing will be well on their way to being solved. One natural development is Voice over Wi-Fi service, which will bring the advantages of VoIP to Wi-Fi enabled devices, such as mobile handsets and laptop computers. And you can expect that many of these new services will have higher voice quality using wideband CODECs. Understandably, mobile phone service providers will compete for phone revenue and time (minutes) inside and outside the home. These types of advanced, seamless services require OEMs to build highly integrated, reliable, and cost-effective home gateways. With the advancements in semiconductor process technology and integration, consumers' market needs will easily be met for VoIP and also for processor-intensive future applications such as video over IP.
*Other names and brands may be claimed as the property of others.
Intel is a registered trademarks of Intel Corporation or its subsidiaries in the United States and other countries.
Copyright c 2005 Intel Corporation. All rights reserved.
