Why Sometimes They Work, and Why Sometimes They Don’t
The Computer Corner
By Charles Miller
In response to the recent column on the subject of Wireless Distribution Service WDS or Wi-Fi range expanders) I received several comments. One reader wrote that everything I wrote in the article was completely wrong, and four others very politely shared that their experiences had worked out well for them because they had not encountered any of the potential problems I warned against when using a Wi-Fi repeater.
Everything I wrote in that earlier column was correct. The reason some people experience different outcomes lies in the fact that there is not 100 percent agreement among manufacturers of wireless hardware. Thus some devices are incompatible with others. People in the IT industry are working hard to remedy this situation though.
The Wi-Fi Alliance is a wireless industry organization that exists to promote wireless technologies and interoperability. The Alliance certifies products that comply with its specifications for hardware and firmware compatibility. If you purchase a wireless product with the Wi-Fi Alliance Certified logo on the box, that hardware meets all the standards and is thus more likely to be compatible with other certified hardware. (Note the qualifier!)
I wrote “more likely to be” rather than “will be” because even when a product is 100 percent compliant with all Wi-Fi Alliance standards, the WDS still might not work. WDS is not a part of the standard, each manufacturer is free to implement WDS in its own way. While a Cisco repeater will work fine with a Cisco router, and a d-Link router works with a d-Link range expander, there is no guarantee the two brands will work correctly connected to each other. The headache this creates for IT professionals such as me, and for users, is that sometimes when a router fails and needs to be replaced, all of the repeaters connected to it have to be thrown out too, even though those repeaters are still in perfect working condition.
Certification of wireless hardware is not mandatory, and the absence of the Wi-Fi Alliance Certified logo does not imply that a product is incompatible. Sometimes, particularly in the case of inexpensive components, a manufacturer will choose to simply leave out a feature. That does not imply that the product is inferior, just basic and inexpensive.
In the days before Windows and OS-X, I was struggling to get a very expensive video card to work with a spreadsheet program. I followed all the accepted procedures and practices but just could not get it to work, so I called the manufacturer for help. The technician there told me to use some configuration settings that went against the norm, so I told him “The IEEE (Institute of Electrical and Electronics Engineers) standard says…” He snapped back at me, “We don’t follow standards, we make em!” That is how it was.
Fortunately, as the personal computer industry matured, manufacturers came to understand it was in everybody’s best interest to agree on at least a few standards. Today a Mac can send an email to a Windows PC and both may connect to the same Wi-Fi. Unfortunately, there are still a few areas where there is not agreement, and Wireless Distribution Service is one of them.
The Wi-Fi Alliance has never been able to get enough manufacturers of routers and range expanders to agree on standards for how to make them all compatible. Wich is why so many IT professionals warn against using wireless repeaters or range expanders. Sometimes they work, and sometimes they don’t.
Charles Miller is a freelance computer consultant, a frequent visitor to San Miguel de Allende since 1981, and is now practically a full-time resident. He may be contacted at 415 101-8528 or via email, FAQ8 (at) SMAguru.com.