Letters

The range of a wireless network

To the Editor:

I read with interest Dr. Matt Lewis' article "A Primer on Wireless Networks" [February 2004, page 69], and I agree the future is wireless. One point Dr. Lewis covered briefly was the range of the wireless network. Although the 802.11g signal may travel 300 feet, the actual working distance will be much less. This is especially true in an office setting with interfering electronic equipment and multiple walls/obstructions (especially walls built with metal studs). I installed a wireless network at my office, and the effective range was less than 50 feet. To get 54 megabits per second (Mbps), the range was even less.

Since even the fastest broadband Internet connection is probably less than 3 Mbps, this may not be of concern. For Ethernet connections between computers, however, this can create a bottleneck in the network. To get around this issue, wireless access points must be installed throughout the building. In my case, I was able to adequately cover the entire building with a wireless router and one wireless access point (approximately 6,000 square feet of coverage).

The wireless network relies on a wired backbone, as the access points need to be hardwired to the network. I used category 6 cables because category 5 was too susceptible to outside interference and there was a loss of signal over long cable spans. Using this arrangement, one can roam from access point to access point with no service interruption. If hardwiring an access point is not feasible, signal repeaters are available, but overall data through them will be cut by 50 percent because bandwidth has to be shared.

James Dom Dera, MD
Fairlawn, Ohio

Author's response:

Dr. Dom Dera raises some very practical points about the actual versus theoretical transmission speed and transmission distance of wireless networks in a real office setting. In the article, I mentioned that wireless "boosters" may be needed to provide wireless signal coverage throughout the clinic. I did not distinguish between hard-wired "access points" and wireless "signal repeaters," but the point is important. Signal repeaters, which may be needed if hard-wiring a clinic is not feasible or not permitted, pick up the signal broadcast from a nearby router or other repeater and then retransmit the signal at greater strength. Access points simply plug into a hard-wired network and allow many points of wireless transmission. The size and shape of the clinic will determine the number of access points or repeaters needed. Category 6 cables allow higher transmission rates than category 5 or 5E (up to 155 Mbps) and thus are less susceptible to signal degradation over distance.

Vital practices need adequate reimbursement

To the Editor:

I completely agree with the aspects of a successful practice detailed in "Five Strategies for a More Vital Practice" [January 2004, page 31]. However, a very significant aspect of practice management is missing: reimbursement and contract management. The insidious undervaluation of physician services has placed extraordinary financial demands on practices across the nation. If a practice does not closely monitor its costs and index its managed care contracts to those costs, no level of investment, systems improvement, governance or commitment to patient service will keep the practice from failing.

Because individual physicians are precluded from group collusion on contract negotiations by antitrust laws, they must be diligent in examining contracts that are historically based on the lowest-common-rate methodology. Physicians must be willing to walk away from low-paying contracts that promise quality-killing volume. Unless a physician or group practice knows its cost profile and is willing to negotiate from a knowledgeable position with a consolidating list of payers, the practice will experience a deceptively gradual deterioration of its profitability.

Dean Norris
Flagstaff, Ariz.

Electronic filing cabinet tips

To the Editor:

After reading "Creating an Electronic Filing Cabinet" [January 2004, page 65], I have a few suggestions. To put it simply, burning and reburning onto rewritable compact discs (CD-RW) is painfully slow; using regular recordable CDs (CD-R) is better. You will need software (e.g., DirectCD) available at each of your computers to read them. If you are prepared to make an investment, you can buy a 20 GB universal serial bus (USB) external hard drive for less than $200 and load the drivers on each computer you use (or carry the drivers on a minidisc). Then you can plug and go. File transfers and searches are fast and easy, and the hard drives are thin and small and can connect to laptops or desktops. I use this system to back up all my office work and bring it home each day to store on another computer and laptop. This makes three backup copies. I also burn CDs once a year to store the past year's work, including letters, medicolegal reports and correspondence.

R. Swarsen, MD
Denver