1. From a technical point of view, what does HomeRF offer which distinguishes it from any other wireless LAN technology?

HomeRF offers high quality, low-cost voice communications, Quality of Service support for multimedia traffic, robust communications in the face of interference, and strong security measures.

As the HomeRF group says, HomeRF was designed for the broadband Internet home. This is more than a marketing generalization; it has concrete technical implications. HomeRF has several technical features that differentiate it from other wireless LAN technologies. These features are designed to make HomeRF optimal for operation in the home environment, an environment in which there will be many different kinds of applications, uncontrollable interference, and no IT professional to secure the network traffic.

1. HomeRF contains, as part of the specification, inherent support for voice communications. This part of the protocol, and the HomeRF technology, is based on the widely deployed DECT cordless telephony standard. Voice communications within a HomeRF network are of the same high quality as users of DECT-based cordless systems have come to expect, and, equally important, the technology takes advantage of the cost curve for DECT technology development. Thus, unlike voice solutions that rely on voice over IP over a wireless link, HomeRF provides a voice solution that is high quality, low cost, and immune from the impact of high network loading.
2. Other applications that are likely to drive home networking adoption are those requiring quality of service (QoS) support, such as streaming audio, streaming video, and gaming applications. HomeRF offers the ability to establish up to 8 simultaneous QoS streams. Unlike regular data traffic, these streams exhibit low latency and low jitter characteristics, exactly what will be needed to enable multimedia applications. The HomeRF organization has a whitepaper that explains QoS in HomeRF networks.
3. As part of its basic design, the HomeRF specification recognizes that HomeRF networks will be located in areas where the interference environment cannot be well controlled. Since HomeRF operates in the unlicensed 2.4 GHz band, HomeRF networks will be found in the presence of microwave ovens, cordless telephones, wireless video cameras, other wireless communications systems like Bluetooth, and other 2.4 GHz wireless LAN systems in nearby homes, apartments, etc. These impediments might not present themselves in a corporate environment, where spectrum usage may be more carefully controlled, but it is highly likely that they will be seen in a home environment. It is for this reason that HomeRF is designed using frequency hopping technology. Frequency hopping permits the system to move away from an interference source, at least some of the time, so that messages will continue to get through, even in the presence of interference. In addition, HomeRF has added intelligent frequency hopping, called hopset adaptation with packet retries. This permits even the voice and multimedia sessions to continue to operate reliably in the presence of interference. The HomeRF group has a whitepaper that explains why HomeRF is robust in the presence of 2.4 GHz interference.
4. Another characteristic of home networks anticipated by the HomeRF technology is the lack of an IT professional who can help to provide network security. While any home network can be made more secure with the addition of end-to-end encryption, securing a network in this way may be beyond the capabilities of many home users. More importantly, even if encryption is used, this will often not protect a home network against more basic attacks, including the popular denial of service attack, in which a network is simply made inoperable. While other wireless networking technologies, specifically those based on the 802.11b standard, have been found to be vulnerable to hackers, HomeRF networks have several layers of protection built-in that make them more secure. The use of frequency hopping, first of all, makes the HomeRF network more difficult to find. All HomeRF networks require the use of a network ID, without which it is not possible to send packets that will disrupt the use of a HomeRF network. And to protect data from compromise, the HomeRF standard defines a 128 bit encryption scheme. The HomeRF group has a whitepaper that discusses security in the context of the HomeRF networking model.

2. Will a HomeRF wireless network (or any other wireless technology) in the home ever be fast enough to handle entertainment distribution ... i.e. Streaming Media or Video on demand etc.?

Absolutely. HomeRF wireless networks are already capable of supporting audio streaming. In the very near future new technologies and regulatory changes will lead to wireless networks capable of supporting almost any type of streaming media imaginable.

Existing HomeRF networks are fully capable of handling streaming audio already. MP3 operates at 64 kbps or 128 kbps, which can be readily handled by either 1.6 Mbps HomeRF networks or, certainly, by the 10 Mbps HomeRF networks. Even an uncompressed CD operates at only 1.4 Mbps.

The real challenge for wireless networks will be video distribution. A DVD, or a single standard definition digital TV channel requires about 3.5 Mbps, which is at the upper edge of the capabilities of present-day wireless networks. The next generation of HomeRF technology, however, will be fully capable of transporting these kinds of data rates. Even 19 Mbps or 38 Mbps digital TV signals will be within its capabilities.

3. How serious of a problem will the congestion of the 2.4 GHz band be for wireless LAN technologies?

Congestion in the 2.4 GHz band will only be a problem when technologies not designed to handle that congestion are used in congested locations. The most robust technologies are the ones most likely to survive in the unlicensed spectrum environment.

Congestion in the 2.4 GHz band is both a real issue, as well as one that is overplayed for strategic purposes.

The unlicensed spectrum bands have been used, historically, under a basic philosophical framework. That philosophy has been that of a "commons". Anyone wanting to use the spectrum can do so, subject only to some basic rules of fairness. No one should overuse the spectrum, and anyone using the spectrum must be prepared to deal with other, legal users.

When products are designed to operate in these bands with full understanding of this philosophy, congestion is not as serious an issue as it is often made out to be. Manufacturers can design products that operate very well under these conditions, and excellent performance is one of the primary methods of product differentiation.

The issue of congestion in the 2.4 GHz band has received a great deal of attention recently because, in certain cases, technologies have been introduced into the band without sufficient recognition of the philosophy of the unlicensed bands. The current generation of 802.11b technology, for example, uses a frequency static technology that contains very little processing gain. This makes it extremely vulnerable to 2.4 GHz interference. In an attempt to protect these systems, some proponents have proposed limiting access to the 2.4 GHz band either by limiting applications or by limiting standards.

The HomeRF group has always felt, and continues to feel, that this is the wrong way to view the unlicensed spectrum bands. Excessive restrictions will stifle the innovation that has been a hallmark of these bands. Rather, manufacturers must recognize the spectrum environment and design products that can handle that environment, as HomeRF as been designed to meet the demands of the 2.4 GHz home environment. If this is done, the 2.4 GHz band will continue to provide a useful communications environment for many years to come.

4. What are the advantages of using a HomeRF wireless network rather than WiFi based, 802.11b?

For users with certain requirements, the advantages of HomeRF over 802.11b are its built-in support for high quality, low cost voice, its support for QoS, its robustness in the face of 2.4 GHz interference, and its inherent security.

This question has already been answered, to some extent, in questions 1 and 3 above. It is, first of all, important to note that the advantages of a HomeRF network attach to where, and by whom, the network is used. HomeRF is more appropriate than 802.11b in certain situations. When the user of the network will demand multimedia services, especially voice services, HomeRF is more appropriate, with its DECT-based voice support and its QoS service support. When the network will be located in an uncontrolled spectrum environment, subject to interference from microwave ovens, cordless phones, other wireless LANs, and other 2.4 GHz transmitters, HomeRF is more appropriate with its robust interference immunity and interference avoidance techniques. And, finally, when the network installer is not expert enough to include advanced security measures, HomeRF is more appropriate with its built-in security precautions.

5. How secure is a HomeRF network? Can a hacker steal my data from the airwaves?

HomeRF presents a difficult enough target to make it unlikely that a hacker will be able to steal your data from the airwaves.

This question was addressed in question 1, above though there is no simple answer to this question. Given enough resources, a hacker can probably steal data from any network, including a HomeRF network. The real question to ask is whether a HomeRF network is secure enough to repel any likely attack from a hacker. HomeRF offers security at many layers, which should be adequate to prevent data from being stolen over the airwaves. a) HomeRF uses frequency hopping which would need to be overcome in order to cause any sort of denial of service attack, or even locate the network in the first place. b) HomeRF uses a secret network ID in order to prevent unauthorized access to a HomeRF network. c) HomeRF includes strong 128 bit encryption in order to prevent compromise of the data on a HomeRF network. The HomeRF security whitepaper is a good place to begin exploring these issues.

6. What other kinds of new home products and gadgets will be using HomeRF.

Voice and streaming multimedia products are the kinds of new gadgets that a HomeRF network enables.

Because of its strong focus on the home environment, HomeRF networks will soon be supporting many kinds of devices not widely deployed on networks focused on the transport of Ethernet-like data. For example:

1. HomeRF voice handsets will be available this year.
2. HomeRF devices to synchronize audio with a car audio system are being developed.
3. HomeRF devices to stream audio content to other devices in the home are being developed.
4. 10 Mbps data networking products, including PC card and USB adapters, and cordless gateways will be available this year.
5. In addition, cable modems and DSL routers will soon be available with HomeRF installed.

7. What is the status of the FCC's current inquiry into the unlicensed spectrum rules, and what will be the likely outcome?

The likely outcome of the FCC's current inquiry will be less restrictive rules, leading to new kinds of technologies in the 2.4 GHz band.

The FCC is currently undergoing a review of the rules that govern unlicensed spectrum. This is part of a proceeding known as Docket 99-231. In this proceeding the FCC has asked many questions, but the overarching question is whether or not the rules governing the use of unlicensed spectrum should be less restrictive. Two of the most specific questions concern whether certain classes of frequency hopping devices should be allowed to use less than 75 MHz of spectrum in the 2.4 GHz band, and whether a new classification of technology, called "digital transmission technologies" should be defined.

While the FCC is early in the inquiry stage of this process, they have already issued a "blanket waiver", authorizing companies to develop and market digital transmission systems without waiting for the end of the current rule making process. It therefore seems highly likely that the outcome of this process will be a liberalization of the 2.4 GHz rules allowing many new types of technologies, including some with much higher data thoughput than the current generation, to be deployed in the 2.4 GHz band. The HomeRF organization has long had a roadmap for an evolution of its capabilities to even higher data rates, while offering full backward compatibility to current technologies. The definition of these new technologies will, of course, be influenced by the outcome of this FCC process.

8. Will the next generation of wireless products have a greater range? Higher Speed? What are the limits?

New rules and new technology will not repeal the laws of physics, so future generations of wireless products will still show an inverse relationship between range and speed. However, data rates will continue to increase, significantly, and manufacturers will be able to provide a wider array of products with range/speed characteristics that meet customer demands.

Because of the likely changes to the FCC's unlicensed spectrum rules, it is very probable that the next generation of wireless LAN products will have greater speeds than the current generation. However, because unlicensed spectrum is a community resource, it is unlikely that the rule changes that lead to greater speeds will also lead to the use of greater powers. That being the case, the age-old tradeoff between data rate and range is likely to continue. That is, in general, systems with lower data rates will be able to communicate over greater distances. Higher data rate systems will operate over shorter ranges.

That being said, however, the limits in this area are market related as well as simply technical. Range can be increased though the use of higher quality, and more costly, technologies and equipment. Exactly where the limits in terms of data rate and range lie is difficult to say. What is clear, however, is that as the rules become less restrictive, there are no foreseeable barriers to the creation of wireless home networks that can support any kind of voice, multimedia, and data applications that we can currently envision. The true barriers are likely to be what consumers will pay to enable the applications they want, not technical or regulatory ones.

The views expressed in this interview are those of the HomeRF group and do not represent any specific company.