Integrated Connectivity for the SOHO Environment, Part Two
By: Dana Whitney, vice president of network products, N/A Inc.
Contents
Sharing the power lines
Phone line networking
The wireless option
IEEE 802.11 wireless LAN
There are three main challenges associated with building a small office/home office (SOHO) network: distributing connectivity in the SOHO, providing a comprehensive gateway for data access in the SOHO, and providing security and control of the connection to the outside world. In this second installment we will look at various options for connectivity.
There are several choices for distributing data in the SOHO: Ethernet, power line, phone line, and wireless. Ethernet appear to be the logical choice given its ubiquitous deployment in the corporate world and would work well in a small office building. However, the work needed to run new wires throughout a typical home is insurmountable in many cases, since most people do not want the wires to be visible. Using a "no new wires" approach is mandatory if the technology is to work in a home office.
Sharing the power lines
If no wiring is to be installed, the network must make use of existing wiring in the SOHO or be build around a wireless technology. The most ubiquitous wiring in most SOHOs are AC power lines and systems exist to provide opportunities to easily connect information devices with a single cord.
For example, Intelogis (Draper, UT) sells its PassPort AC power line adapters come in the form of a $199 kit, which includes two adapters that connect to the PC via a parallel port. The kit also includes a separate adapter for a printer, so it can be on the network as well. Additional PassPort PC and PassPort Printer Plug-In adapters are available separately for $79 and $59 respectively.
This AC power line system offers about 350 Kbps raw data transfer, according to Intelogis, although the company has demonstrated 10 Mbps technology. While the lowest-cost SOHO networking solution on the market, and arguably the easiest to install (assuming the PC recognizes the devices) this technology has proven to be difficult to cost-effectively implement for high data-rate LAN applications.
Phone line networking
The other plentiful source of preexisting wiring in most SOHOs supports the telephone. The Home Phoneline Networking Alliance (HomePNA) is an industry group that standardizes and promotes this technology. Many vendors are currently selling 1 Mbps home LAN cards for PCs. This solution is cost-effective and fairly robust, even in the presence of baseband telephone activity on the same wires.
The HomePNA has finalized the standard for a 10 Mbps implementation. Due to these 10 Mbps products, this area has gained a lot of momentum in the past month. Networking equipment vendor 3Com (Santa Clara, CA) is now shipping the 3Com HomeConnect Home Network Phoneline, a 10 Mbps product that uses existing home phone wires and jacks to connect multiple PCs.
Another shipping product, from Irvine, CA-based Linksys, is the HomeLink Phoneline Network in a Box, a product that offers connectivity to multiple PCI bus-equipped PC's. The advantage to these systems is that there's no need for a switch, a hub, or RJ-45 Ethernet cabling, the network runs on standard home-grade telephone cables. Simply install the kit's cards, plug the provided telephone cables into the wall, run the installation software, and go.
The wireless option
The third approach to distributing connectivity in the SOHO is wireless radio technology. Until recently, robust wireless LANs have been expensive, geared toward vertical application (such as warehouse inventory systems), and complex to implement. With higher levels of chip integration, these devices are now cost-effective for traditional LAN use. This has the advantage eliminating the need for wires and existing wiring to connect computers and other information devices to the rest of the world.
There are several industry groups that are working on standards for wireless devices. These include the HomeRF Group (San Francisco) that has developed a specification for wireless communications in the home called the Shared Wireless Access Protocol (SWAP).
Another group is the Bluetooth effort. Conceived in 1998, Bluetooth technology is designed to eliminate the cables needed to connect mobile communication devices, mobile computers, and peripherals. Bluetooth technology will enable users to connect their mobile computers, digital cellular phones, handheld devices, network access points, and other mobile devices through a short-range 2.4 GHz radio link.
The first specification for Bluetooth was released in July of this year. A variety of Bluetooth products will hit the market early next year. Companies, such as IBM Corp. (Armonk, NY), Nokia (Espoo, Finland), and Toshiba (Tokyo), are all working on solutions that employ the Bluetooth specification.
Both SWAP and Bluetooth wireless technologies are geared to 1 Mbps or slower data speeds and have limited range. Also many implementations have serious operational issues when used with more than three devices.
IEEE 802.11 wireless LAN
An arguably more robust wireless LAN standard has been defined by the Institute of Electrical and Electronics Engineers (IEEE). The IEEE 802.11 wireless LAN standard includes definition of devices that operate up to 11 Mbps, with 2 Mbps products already on the market and 11 Mbps devices are under development.
Although currently more costly than Bluetooth or HomeRF devices, 802.11 compliant products provide much higher throughput and more robust performance, especially when several devices are on the network. The advantages of 802.11 are built-in security features and compatibility with corporate wireless networks.
Regardless of the media that wins the SOHO networking battle, standards are key to ubiquitous deployment of technology. Given the current landscape, it appears that HPNA phone line devices will be the most cost-effective distribution media for data in the SOHO, while 802.11 wireless LANs will be used in less cost-sensitive situations and by people who need the mobility of wireless.
With the definition of standards-based LAN technology for the SOHO, many people in the industry think the SOHO networking problem is solved. However, it is only the first hurdle to widespread acceptance of broadband connectivity and SOHO networking.
In the next installment, we will look at the gateway, the centralized control point that is critical to the success of SOHO networks.
About the author:
Dana Whitney is the vice president of network products for Zoom Telephonics Inc., a Boston, MA-based supplier of modems, dialers, and wireless networking equipment.