Wireless Microphones and Wireless Guitar Devices
Wireless microphones and wireless guitar devices are going to begin competing for the same bandwidth as digital television and unlicensed wireless devices like portable phones, mobile PDAs and gaming devices. All these new devices need to be able to send and receive information through the airwaves and to be able to do it securely. Not only are there many more devices demanding to use bandwidth but they have increasing needs for dense use. In other words: your iPhone is capable of streaming audio and video over the airwaves. That takes up a lot of airwave ‘space’. This is only one example of many different types of devices.
Broadcast bandwidth is finite: there is a definable amount. Traditionally, the available bandwidth has been sliced up and allocated to specific uses. Television used the most and therefore got the lion’s share of available space. The rest was split between AM radio, FM stereo radio, police, fire, air traffic and emergency frequencies and a large chunk for military use. Some was set aside for public use for radio operated toys and similar devices.
Technology marches on – as always. Houses started to use remote phones, cellular technology caught on and grew like wildfire, bluetooth, hand-held communicators, and so on.
The music industry settled on something known as the ‘white spaces’ between UHF and VHF television allocations. This space has been successfully and dependably used for wireless microphones, headsets, guitar devices, etc. Full frequency broadcast of sound is reasonable dense – it requires a fair amount of clean airspace. The available ‘white spaces’ have worked well for decades.
Major productions like large concerts have a large number of wireless microphones, headsets and instrument devices all operating simultaneously and separately (without interfering with each other). Not only are there performers onstage but the stage crews also operate with 2-way wireless communication devices in order to be able to coordinate the show. Every one of these devices needs to work dependably without interfering with any other device. Needless to say, all the devices need to operate without picking up any other air-born signals (TV, FM or AM radio, police, fire, emergency, air traffic control, military, sport, etc.).
On November 4th, 2008, the FCC voted 5-0 to approve new uses for white spaces. Their intention is to provide more bandwidth for Wi-Fi and other technologies and to increase their reliability. This is supported by the many Wi-Fi device manufacturers and users. Unfortunately, this is the space used by music industry devices. The new challenge is for music industry wireless device makers is figure out a way to keep the millions of Blackberries, iPhones, and Wi-Fi routers from disrupting wireless users.
It will probably be at least two years before any of these new wireless internet devices are deployed, giving music industry wireless users time to prepare. Mark Brunner, senior director of public and government relations at Shure has said: “The FCC has been receptive to many of our suggestions. We have also seen nothing to suggest that wireless users won’t still have access to the entire UHF spectrum. Existing systems will continue to function.”
FCC Chairman Kevin Martin stressed that precautions would be taken to head off potential problems. He said: “We have been cautious in our approach. Significantly, the Commission embarked on extraordinary testing. For months, both proponents and opponents of opening the white spaces participated in laboratory and field testing conducted by our engineers.” He also noted that all “unlicensed” white space devices must include “geolocation capability” and “spectrum sensing technology” that will “tell the device what spectrum may be used at that location.” This is a neat idea but it may not work well in the ‘real world’.
The change-over date is February 17th, 2009 for changes to digital television broadcast in the core TV spectrum. The FCC ruling means that all the other digital devices can begin using the white space spectrum at that time.
One of the key issues to be decided in the coming months is the certification process for geolocation capability and spectrum sensing technology. A coalition of several hundred artists, running the gamut from Miley Cyrus to Megadeth, have made their concerns clear, noting, “This solution (geolocation and spectrum sensing) is wholly insufficient for live performance productions. Shows in 60,000-seat stadiums or even 250-seat nightclubs would be brought to a screeching halt every time one of these new unlicensed devices requires a sensing patch or when the device owner decided to modify his or her device with an aftermarket power booster.” William Wrightson, Guitar Center’s vice president of merchandising, presented similar concerns to the FCC, writing: “We believe parties who support the introduction of new TV-based devices have the burden to demonstrate that the new devices will not interfere with existing use of this spectrum.” The Sports Technology Alliance, which includes the NFL, Major League Baseball, NASCAR, the NHL, and the NBA, was even more critical, writing, “The FCC’s own engineers and data fail to demonstrate that the technology works better than 50% of the time in a real-world environment, and in many cases failed miserably. We therefore request that the Commission not authorize the demonstrably unreliable technology of spectrum sensing as a basis for permitting the production of potentially millions of interference-generating devices.” Others who have joined in requesting that the FCC delay allowing unlicensed devices access to the TV spectrum include Sen. Hillary Rodham Clinton (D, NY), Pastor Rick Warren, Dolly Parton, Guns N’ Roses, the Grand Ole Opry, the Shubert Theater Organization, Harrah’s Entertainment, the American Federation of Musicians, the Country Music Association, and The Recording Academy.
Shure engineers are exploring a variety of alternative wireless technologies. It would appear that technological solutions can be found but they may be at the expense of the owners of the current devices (that may no longer work dependably). There is a monetary incentive for wireless device manufacturers to come up with new solutions since that will require replacement of all existing equipment. The existing systems are not cheap but may soon be obsolete.
Information assembled from numerous news articles and industry white papers.
Special note of credit to musictrades.com – The Music Trades Online
Ⓒ 2008, Leonard Wyeth