Cable Eyeing Bluetooth
for Home Networks
by Ken Freed.
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Cable operators considering wireless links, but plenty of issues confront deployment.
 

While the idea of using anything other than coaxial or fiber lines seems ideologically anathema to old cable hands, the possibilities for a wireless home network are being explored by U.S. cable operators.

"We are presently in the process of developing a technology and business strategy for home networking," said Steve Craddock, VP of new product development at Comcast Communications. "We've begun evaluating all the wired and wireless technology out there to see what we could use, doing some work through the CableLabs 'CableHome' project, and some on our own."

Comcast's view, he said, "is that most cable customers will need the 'no new wires' approach because of when and how their homes were constructed, and that means a wireless solution. At first we threw out wireless as an option, but we've mellowed a bit."

The idea of wired versus wireless as a quasi-religious war is fading on both sides," said Andrew Kreig, president of WCAI, the Wireless Communications Association International, formerly the "wireless cable" trade association founded by cable pioneer Robert Schmidt.

"The concept of a home wireless network is increasingly attractive as an efficiency creator for a seamless network of high-capacity devices in the home," Kreig said. "Among five competing wireless standards, three of them may be compatible with cable equipment for home networking. Now the issue is how to build the most efficient home network. No one's talking about wireless as an end in itself, but wireless will be an inevitable component in many cases."

The leading option for a wireless interface seems to be "Bluetooth," backed by Nokia, Intel, Microsoft and others. Initially developed by Ericsson as a replacement for a wired Ethernet local area network (LAN), Bluetooth today can be licensed free from Ericsson upon agreement to implement the Bluetooth specifications exactly -- no wiggle room for spoiling worldwide interoperability.

The American-based "HomeRF" platform has Apple's backing for linking peripheral devices. Rivaling Bluetooth and HomeRF both is the "IEEE 802.11" standard for the wireless local area network (WLAN), carrying the global gravitas of IEEE.

All three wireless interfaces operate in the 2.4 GigaHertz (GHz) bandwidth within a maximum range of 100 meters (about 333 feet). An 802.11 device can mange 10 megabite per second (Mbps). HomeRF devices offer DSL speeds of 1.6 Mbps today with 10 Mbps expected by late 2001. Bluetooth today peaks at 721 kilobits averaging about 500 Mbps, staying inside a range of 10 meters for most applications, but 10 Mbps within 100 meters is within the latest Bluetooth spec.

 

Bluetooth History

Why does Bluetooth have the most industry buzz? "You have to appreciate the history of Bluetooth," said David McCall,

senior applications engineer at chipmaker Cambridge Silicon Radio (CSR) in the UK. "The first thing about Bluetooth that the people at Ericsson talked about nearly five years ago was a marketing document. "They saw the global market for a low-power, short range wireless LAN solution, and Bluetooth's technical documents grew from that marketing document. This is reflected in the applications included in the 13 Bluetooth profiles," mostly for PC-centric devices.

"Ericsson quickly decided not to keep Bluetooth to themselves and not to charge a license fee," he continued, "because they recognized from the start that having a large slice of a small pie was not as good as having a reasonable piece of a large pie that's growing."

Cahners In-Stat estimates there will be about 1.5 billion Bluetooth devices in the world by 2004. Already in the marketplace are 128 "Bluetooth-qualified" consumer electronics products with Bluetooth chipsets -- laptops, PDAs, printers, cellphones, headsets, mp3 players, and other devices, Signaling Bluetooth's reach into cable, Scientific-Atlanta agreed to support a Bluetooth PCMCIA smartcard with a slot in the advanced Explorer digital set-top boxes.

"If you look at Bluetooth development from the viewpoint of cable manufacturers," said Joyce Putscher, director of consumer and converging markets and technology research for Cahners In-Stat Group, "the one prevailing interface is Ethernet. Cable modems have Ethernet ports. All you need do is extend that into the cable set top box, so you can access a home network from the modem or the box."

"One of the features that makes Bluetooth technology attractive to a number of companies is that it is designed to be very low cost," said wireless analyst Navin Sabharwal, VP of residential and networking technologies at Allied Business Intelligence. "When Bluetooth version 1.1 is finalized this year, its capabilities will become more robust, but cable applications are uncertain. Among the 13 Bluetooth application profiles, not one is specifically for cable home networking, but the wireline profile can be applied."

Craddock described deliberations at Comcast. "We saw that Bluetooth, 802.11 and HomeRF all compete in the same [2.4 MHz] bandwidth, and we felt only 802 could really deliver the bandwidth and range we needed. We still feel that way, but Bluetooth will be in a lot of devices regardless of anything we do. To ignore it means we ignore all those devices, which we can't do. So we will have a Bluetooth interface to talk with those devices."

Risks and Benefits

Do health concerns about wireless cellphones apply to wireless home networks?

"I've not heard of health issues raised about it," Kreig said. "If you take the power levels acceptable for cellular mobile phones and apply them to other exposures, radiation diminishes markedly with distance from the source, so I think one would find the exposures are rather less for home network with lower power levels. However, there is no litmus test on [RF] radiation."

The lack of research to develop a litmus test is exactly what bothers some wireless critics, who fear the industry might one day be found liable for harming public health, treated in court akin to tobacco. This risk offputs cable operators. Shielded coax cables emit low EM fields, and laser-pulse fiber lines even less radiation. Why take a chance?

According to David Ethridge, director of product marketing for

Ericsson home communications, "Bluetooth offers many benefits for digital cable operators using a Bluetooth access point in the home."

Options include household automation though the TV set, such as controlling the thermostat or security system. A Bluetooth link to a computer printer can deliver cable coupons and special promotions.

Interactive TV applications include using Bluetooth to sync up a set-top's box with the channel preferences of a person walking into the room, picking up the persona's identity from a PDA or cellphone. Or the Bluetooth network could alert the home subscriber (using any device) when a program about a pre-selected topic is scheduled, then ask if the show should it be recorded to the set-top hard disk.

"I can easily imagine cable operators proactively pushing Bluetooth services to their customers," Ethridge said. "They don't have to stop at selling cable modems and hard-wired home networks. When all the devices in the home can recognize each other with Bluetooth, think of the possibilities."

"Some major cable players are looking into wireless," said Putscher, "but it's so early in the market that no one is ready to talk about it publicly yet."

"The migration of a wireless cable interface from the cable modem to the cable box and then a home network terminal will not take place overnight," she said. Look at how long it's taken to put a cable modem into the set-top box. Cable modems were in only 18 percent of all the digital boxes in 1999, yet In-Stat projects that modems to be in 89 percent of the boxes by 2004."

Putscher expects slower cable penetration for Bluetooth. "I've spoken with cable people who say they won't be ready to make any Bluetooth announcements for at least six months. Talk to me then."
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The Five Wireless Standards

Leading the list of wireless contenders might be Bluetooth, an "open standard" for local networking owned by Ericsson, licensed for free by more than 2000 signatories worldwide upon their agreement to implement Bluetooth hardware and software specifications exactly. Early Bluetooth backers included Nokia, Intel and Microsoft. Bluetooth operates at a peak data rate of 721 kilobits per second (Kbps) in the 2.4 GigaHertz (GHz) bandwidth of the radio frequency spectrum. Typical speeds average 500 Kbps, not enough for video, but enough for streaming mp3 audio. For robust Internet access, Bluetooth is at least ten times faster than a 56k connection. Also popular worldwide is IEEE 802.11b ("Wi-Fi") and soon the 802.11a standard for wireless local area network (WLAN) in the enterprise, home and public arenas. Akin in speed to slow cable modems, 802.11 systems operate at 11 Megabits (Mb) per second in the 2.4 GHz bandwidth inside a range of about 100 meters. An IEEE standing grants global gravitas to the 802.11 wireless standard. Gaining ground in the North American market is the HomeRF wireless standard from the Home Radio Frequency Working Group, which includes Apple Computers for its wireless "Airport" links to USB devices. Again operating at the 2.4 GHz bandwidth within a 100 meter radius from the WLAN transceiver, Home RF devices transmit and receive at DSL speeds of 1.6 Mbps today, with 10 Mbps products expected by late 2001. Not for cable is the Digital Enhanced Cordless Telecommunications (DECT), operating at a data rate of 552 Kbps in the 2.4 GHz band in North America and dedicated spectrum of 1.9 GHz in the rest of the world. Most popular in European homes, DECT mainly is used for cordless voice telephony. The Infrared Data Association is offering IrDA, transmitting data at 4 Mbps though thermal radiation, heat waves, essentially, which means it does not use any RF bandwidth. Hindered by interoperability issues among devices, IrDA is intended for limited short-range wireless links between laptops, printers, PDAs, and cell phones.