White Space competitors fight dirty
Microsoft kicked our TV off the air
Microsoft and Spectrum Bridge, both competing to provide databases of available White Space radio frequencies, stand accused of demonstrating surprising incompetence in managing their own meagre spectrum use.
Filings with the FCC argue that neither Microsoft nor Spectrum Bridge should be allowed to run White Space databases, as both companies have recently managed to break the rules on spectrum use. The filings argue that Microsoft is narrowly avoiding – and Spectrum Bridge is creating – just the kind of problems that opponents of White Space, from Dolly Parton to the Church of England, feared.
White Space devices use the same frequencies as TV transmissions, only in different locations. So the frequency for transmitting BBC1 in London is considered White Space in Birmingham, and the FCC (and Ofcom) wants to open those spaces up to unlicensed devices operating in what the proponents like to call "white-fi".
But to avoid interfering with television the devices need to check with an on-line database to see which bands are available locally, and it's the running of those databases which is still being sorted out in the USA.
Nine companies have been awarded the task of running the databases, and have started compiling their data while working on interface standards to synchronise by. Microsoft comes late and hoping to be number 10, but, along with Spectrum Bridge, has been accused of playing fast and loose with the regulations during the recent National Associations of Broadcasters (NAB) show in Las Vegas, and CTIA in Orlando.
During the NAB show Microsoft applied for an experimental licence to demonstrate White Space technology, but according to FCC filings (pdf)from the Engineers for the Integrity of Broadcast Auxiliary Services Spectrum (EIBASS) Redmond failed entirely to check the bands used by local TV stations before applying for a show licence, and didn't coordinate with Society of Broadcast Engineers as required by that licence.
The filing claims that if the discrepancy hadn't been noticed a sharp-eyed EIBASS member then Microsoft could have knocked out TV transmissions across Las Vegas (as their licence was not restricted to the convention centre).
EIBASS also reckons that Microsoft's submission, which was filed with the FCC on 18 April (pdf), fails to include TV Relay stations in a list of data to be synchronised between databases - though reading Microsoft's filing that looks like pedantry to us.
Meanwhile the NAB itself has accused Spectrum Bridge of knocking out wireless microphones being used by CNBC at CTIA in Orlando. In its filing (pdf) the NAB claims the company was broadcasting from its booth at the show without any appropriate licence at all.
The filing claims that Spectrum Bridge ran a transmitter at 656MHz from its booth during the CTIA show, in clear breach of its experimental licence which only permitted demonstrations at 174-216MHz.
That transmission knocked out wireless microphones used by CNBC in exactly the way that the opponents of White Space devices had feared. The CNBC chaps were able to retune to different frequency, but a less-experienced outfit might have been left unable to broadcast.
Having traced the interference, the CNBC engineers apparently approached the Spectrum Bridge stand to ask if they were aware of the infringement. Stand staff told them that a licence had been obtained, but that the licence number or frequency covered weren't handy. Shortly after the enquiry was made the transmissions apparently ceased.
Both complaints conclude that any company unable to follow the rules can't be trusted to hold the data on which everyone else will rely to avoid similar infractions, and they may have a point.
"These failures demonstrate that Microsoft lacks the necessary regulatory awareness to manage a critically important database," says the submission from EIBASS, which also points out that Microsoft is a late comer to the White Space database game – having filed its request 15 months after the FCC closed to submissions.
The concern here isn't that some wireless microphones had to be retuned, or that Microsoft forgot to phone the right person in Las Vegas prior to a show, but it does show how easy it is to get White Space wrong. The USA, closely followed by the UK, is about to throw its broadcast-TV frequencies open to anyone who wants to use them with only the databases providing some measure of protection. But if the people running the databases don't know what they're doing, then what hope do the rest of us have? ®
The regulator is best and only qualified to run the databases
FCC and Ofcom are abrogating their responsibility. They issue licences and allocate spectrum. They should ALREADY have the needed databases, since the 1970s, or WHAT ON EARTH are they doing all day?
Microsoft can't be trusted! Shock horror!
Well, that really comes as a surprise to me....
Mine's the one with the <sarcasm> tags in the pocket.
Well, for one, that means binning all legacy systems that don't send the "I am here"
For a second, that will completely screw up the intended transmission modulation of the "I am here" beacon
For thirds, televisions are supposed to be receive only. If they tried to transmit an "I am here" on the frequency they were listening to, what do you think would happen to what they were receiving? not to mention a significant part-number increase for the transmitter...
Fourth and finally, there are an absolutely huge number of places where if the TV multiplex transmitter were sending the "I am here" (hint, it is ALREADY sending a known modulation pattern, you'd think that would be enough?), it would be exactly as receivable to the white-fi unit as the TV signal, that the houses are using a nice, big, high-gain antenna to receive. Chances are that the little omni stick used by the white-fi would never hear the TV signal. But would be more powerful locally than the TV signal.
Detect and avoid provably does not work. Databases are the fall-back position (and there are examples where they won't work even when competently implemented) and depend on the competence of the administrators.
Mine is the one with the little SDR receiver in the pocket.