(link) CogNeA is pushing their standard into ECMA.
CogNeA contributed its specification to Ecma’s TC48-TG1 that will further develop it and plans to finalise the 1st edition for publication by the end of 2009. The Standard comprises Physical (PHY) and Medium Access Control (MAC) layers that include interference-avoidance mechanisms. The Physical layer, interference-avoidance and cognitive radio technologies, will be specified such that other wireless networking standards, looking to operate in the TV whitespaces, can use it.
(link) Wi-Rider is a new Georgia Tech spin-out that looks like it’s coupling a REM-like collection of databases with a networked centralized manager for radio resources. Here’s their tech brief. Based on their website’s presentation, I think this is intended as a piece of CogNeA.
ECWS Presentations from 802 Plenary
While I wasn’t there , the March 802 Plenary had a major presentation from the ECWS (in fact it was the primary deliverable for the group.) Based on email traffic I’ve read, it looks unclear at this point in what form this will be continuing on as. [Update 3/16/09 – ECWS disbanded, coexistence work continues in 802.19 as a study group with the outputs of two documents “one on coexistence scenarios and one on coexistence mechanisms, with a plan for when the deliverables will be completed, with interim steps” (802.19 note from here and ECWS disbanding coming via email)]
Nonetheless, if you want to get up to speed on their activities, these two links will do a good job.
(pdf) Tutorial. Quite a large file (~ 7.25 MB), but lots of good information.
(ppt) ECWS Chair’s Report. (Just main takeaways from tutorial and much smaller)
(pdf) Spectrum Sharing in TV White Space Workshop.
As part of its June meeting in Detroit (June 15-18), the SDR Forum will host a workshop on coexistence of TV white space devices on June 16. They’re currently soliciting proposals for presentations through April 1.
(no link) Cognitive Radio and Intelligent Transportation Systems at SDRF ITS Workshop
Intelligent Transportation Systems effectively apply the concept of a cognitive system to the management of transportation systems (gather information, recognize patterns, apply rules / reason, learn from past actions). Wireless links play a big role in transferring information and control messages and cognitive radio can help improve the communications quality and availability in this highly dynamic environment. Once cognitive radio is integrated into and fielded with ITS, we’ll have “cognitive systems of cognitive systems”, which is one of the broader trends I see for the future.
As of this week, I’ll be giving a 30-minute talk with Ashwin Amana on cognitive radio and intelligent transportation systems at the SDR Forum ITS Workshop, also at the SDR Forum Detroit meeting (so many great workshops crammed into such a short meeting).
(link) IWCE Panel to Discuss Cognitive Radio
Really, it’s a panel to highlight NIJ’s communications related research efforts. But one of the major thrusts has been cognitive radio. Charles Bostian of VT will be discussing their NIJ-funded efforts to create the Public Safety Cognitive Radio (PSCR) node. IWCE is March 16-20 (Vegas), and the panel is on March 18th, from 1:30-2:45 PM.
(link) EMC Electronica article on embedded SDR and CR.
Not the most illuminating article, but it does note the natural relationship between SDR and CR (though very DSA focused) and the role of embedded processing in realizing CR. Really, this is just an excuse to note that CRT is currently executing a SBIR to realize embedded cognitive spectrum management on JTRS radios (JTRS defines a DoD standard for SDR platforms). (pdf of a flyer we pass out on the topic)
(link) New CR Blog
I don’t know who he is, but James (not me) is posting his notes on his “4th year project on cognitive radio” as it progresses. At least so far, he’s doing a good job of capturing and linking to important papers.
Conferences and Contests
(link) The SDRF sends a reminder that abstracts are due March 20.
(link) The 3rd annual Smart Radio Challenge is now open.
(link) 12th Annual Conference on Modeling, Analysis and Simulation of Wireless Mobile Systems will have a cognitive radio track. It’ll be in the Canary Islands. Key dates:
Paper submission deadline April 25, 2009
Notification of acceptanceJuly 5, 2009
Tutorial submission deadline June 5, 2009
Workshop submission deadline March 30, 2009
(link) In conjunction with WiOPT09, RAWNET – The 5th workshop on Resource Allocation, Cooperation and Competition in Wireless Networks – is inviting papers on cognitive spectrum management. The conference will be held in Seoul on June 27, 2009. It’s particularly interested in papers related to the cooperation and competition in wireless networks.
Extended submission deadline : March 15, 2009
Notification of acceptance : April 1, 2009
Camera-ready papers due : May 1, 2009
White Space Related News
(link) WIth some public safety entitites, the CTIA urges ban of secondary access in 700 MHz. Looks mostly focused on clearing out legacy wireless microphones and ensuring that white space devices don’t creep up the spectrum.
(link) NAB is suing to try and block white space devices. This surprising to me as I thought geographic databases and non-adjacency were what MSTV and NAB were looking for. The suit certainly colors my opinion of MSTV and NAB’s efforts viz a viz the white spaces.
(pdf) Stealing a march on the White Spaces Database Group, SpectrumBridge announced the creation of a on online website (ShowMyWhiteSpace.com) to identify available whitespaces by geographical location. It failed for my house, but worked for the White House. (Guess I’m not important enough)
white space database screen capture
Though the term was first applied to WiMAX (link), “WiFi on Steroids” now commonly refers to a use-case for the white spaces (link) for WiFi-like access points in the UHF bands, but better, stronger, faster and so on due to the ongoing advances in technology.
As an initial business model, it’s a good place to start as there’s ALOT of demand for high-speed access at the home as evidenced by WiFi and if someone can build a better WiFi access point, the world should beat a path to their door.
However, I don’t think we’ll be able to successfully market white space devices as WiFi on Steroids.
All else being equal, you get higher data rates (what most people think of for “WiFi on Steroids”) by either grabbing more spectrum or using spectrum more efficently. Sure, as a nation, allowing the opportunistic use of unused spectrum improves nation-wide spectral efficiency, but it doesn’t improve spectral efficiency for a given link. Which means that on its on, you’re not going to be squeezing higher peak bps/Hz over your WiFi link just because it’s now running DSA. In other words, simply downbanding WiFi won’t get you massively increased throughputs that would be required to encourage people to abandon their ISM-band WiFi. Augment, maybe in a dual-mode cross-band channel bonded mode to increase throughput, but the extra front ends and necessary isolation seems expensive and wouldn’t be anything that couldn’t theoretically be done with ISM and UNII bands and dual RF ports, which isn’t exactly driving the WiFi market now.
That means that in order to increase data rates up, we’ll have to use wider bandwidths or improve spectral efficiencies the old fashioned way, i.e., higher-order modulations and / or antenna arrays (ala .11n). Since I don’t think that in practice we’ll be using higher-order modulations, that leaves antenna arrays. Typically, that means MIMO (which in its own way is grabbing more “bandwidth” via spatial channels). But for MIMO you need low spatial correlation, which in practice means antenna spacing that is a significant fraction to multiples of a wavelength. I’ve seen studies showing gains for as low as quarter wavelengths, but a full wavelength or more is the rule of thumb.
But what’s a wavelength in the UHF bands?
To simplify the math, let’s use 300 MHz (right in the middle of the band). The wavelength is then 1 meter (a little better than half your height) which is not a good form factor when compared to the 0.125 m (3e8/2.4e9) spacing for the ISM band.
So perhaps we just grab more spectrum to offset the MIMO loss (roughly, call it a factor of 2 loss that from not being able to use MIMO), which is reasonable because the spectrum is free.
That may not be much of an option in the big cities where the customers are. The studies I’ve seen have shown 14 available channels in a city such as LA once channel adjacency requirements are met. That means there’s 6×14 = 84 MHz, which is not much more than what is used in the the ISM band (e.g., 79 1 MHz channels in Bluetooth). Sure there’s a lot of interference in the ISM bands now, but with longer propagation in the UHF bands, interference will quickly become a factor there too.
Now there are creative ways to get around this, particularly with cooperative / synthetic MIMO techniques (e.g., co-deploying UHF-WiFi with your home stereo system to use the speakers as widely separated antennas or just add on antennas with wires for your WiFi AP), but they’re kinda klugey and not with the plug-and-play factor that gave WiFi it’s mass appeal.
So in short, I don’t think the WiFi on steroids as it relates to higher data rates makes much sense as a business model / use case. And since it’s been marketed as “WiFi on Steroids” (much higher throughput which I think is not possible in the most valuable markets) and not just a different band for WiFi (ala the differing bands for cordless phones), I think the market will be really slow to adopt these devices.
What I think may make more sense are applications that don’t need as much throughput (so exotic channel bonding techniques aren’t required) but would benefit from better coverage (due to the downbanding) and free spectrum. For example controls sorts of applications ala zigbee (cognitive zigbee if you will) makes sense for home automation applications and factory applications and meter reader sorts of things (which for maximum buzzword density makes white space devices a good candidate for supporting the smart grid). These sorts of coverage (range) intensive, but low throughput applications are what I think will win out in the coming white-space deployment race.
(link) OfCOM’s proposed rules for interleaved spectrum access. Like the FCC, it’s also a mix of sensing and geolocation.
Beyond the launching of the database group news below.
(link) White spaces may be coming to Europe.
But the UK is not the only market in Europe, and in less space-restrictive countries it could be practical to utilise white spaces, which explains the White Space Coalition launching a European campaign at the European Conference of Postal and Telecommunications Administrations.
Dr. Alexandre Kholod, of the Swiss Federal Office of Communications, told PolicyTracker, after the meeting, that he didn’t see much spectrum available once mobile and PMSE* applications had been served. The French spectrum agency, ANFR, is preparing a report on the subject of white space use in France, but there are significant concerns about the ability of cognitive radios to avoid TV transmissions.
(link) Canada too. Though their transition isn’t until 2011 so they have some time. Since it’s hard to find a good excerpt, here’s my quick summary. The Canadian Radio-television and Telecommunications Commission (CRTC) is holding hearings starting Feb 17 where white spaces are expected to come up. The CRTC regulators have apparently been following along with and interacting with the FCC efforts.
(pdf) Ofcom released ERA Technology Limited’s analysis of hidden node margins for cognitive radio devices in TV bands (B.S Randhawa, Z. Wang, I. Parker, “Anaylsis of hidden node margins for cognitive radio devices potentially using DTT and PMSE spectrum”). Excerpts from the summary and conclusions:
In the Digital Divident Review (DDR) statement Ofcom indicated that cognitive radio devices (CRD)s will be allowed to use the interleaved spectrum subject to being satisfied that they will not cause harmful interference to digital terrestiral television (TT) or programme making and special events (PMSE) applications. A cognitive device will therefore be required to monitor the UHF band for DTT and PMSE transmissions before being allowed to transmit on locally unused channels.
A short project was previously undertaken by ERA to determine indicative values of the hidden-node margin through direct measurements. This trial estiamted that the average hidden node margin for a cognitive radio device to sucessfully detect a DTT signal at 1.5 m for approximately 90% of all locations, was about 25 dB but in some situations a marfin of 30 dB or greater could be required.
The hidden node calcualtion was bound to an ara defined by the unwanted cognitive interference being greater or equal to the received wanted signal minus the co-channel protection ratio of 25 dB and an extra fade margin of 25 dB, based on the assumption that if the level of inerference was less than a sensitivity level of -117 dBm the cognitive rdevice would not cause interference to the PMSE receiver.
(link) Yesterday, Google et al announced the formation of a group to standardize whitespace database information.
With a goal of bringing the benefits of white spaces to consumers as soon as possible, the Group intends to establish data formats and protocols that are open and non-proprietary and will advocate that database administration be open and non-exclusive.
[somewhat reordered paragraphs] Founding members of the White Spaces Database Group include Comsearch, Dell, Google Inc., HP, Microsoft Corporation, Motorola Inc., and NeuStar.
(link) The Google public policy blog added:
In the coming weeks and months, members of the group will be offering to the Commission their perspectives, and some specific recommendations, about the technical requirements we would like to see adopted for the database. Many of these specifications ultimately will be heavily technical; put simply, we’ll advocate for data formats and protocols that are open and non-proprietary, with database administration that is also open and non-exclusive.
We don’t plan to become a database administrator ourselves, but do want to work with the FCC to make sure that a white spaces database gets up and running. We hope that this will unfold in a matter of months, not years.
Following up on the earlier news that Obama wanted to delay the DTV transition, there’s been a couple major events the last two days.
First, on Monday, the Senate passed a bill delaying the transition to June 12. Then yesterday, the bill failed in the House.
So we’re back on schedule. For now.
(link) Off again. Probably until at least June 12 now.
Congress yesterday approved a four-month delay in plans to halt analog television, the latest chapter in a troubled effort by the government to clear airwave space for emergency responders and wireless services by moving millions of households to digital television.
Pat Carson from TDK gave a short presentation on CogNEA today at the SDRF CRWG / Secondary Spectrum Test Group joint meeting and said the information was for public consumption, so here’s some info in addition to the earlier press release.
1) CogNEA is basically the technical side of the White Space Coalition (the lobbying side). (TDK was a member of the WSC)
2) CogNEA is nominally now “open” for membership, but the new membership process has not been defined.
3) The standard CogNEA is developing defines a PHY, a MAC, and the extent of the cognitive capabilities is geolocation + sensing. Unlike the 802 ECWS plans, there is no current plan for the standard to have [explicit coexistence capabilities - ed, wow, I left that sentence unfinished for a week.]
4) CogNEA is intending this for the following applications: In-home High Definition MultiMedia (HD MM) but not wireless HDMI, Networking and distribution solutions that overcome the whole home coverage problems inherent to solutions using ISM bands, Internet Access for communities, neighborhoods, campuses, Ad-Hoc Mesh networks, Tele-health, Home automation and control. Currently these are handled by different standards (e.g., Zigbee, WiFi, Bluetooth) but the PHY is intended to handle everything (basically WLAN and smaller).
5) The Standard was at V0.70 the last time Pat checked, but it may have been updated at the ECWS meeting (the CogNEA meetings have been going on as sidebars at related meetings). The plan is to bring it to a SDO such as ISO in mid-2009.
(pdf) (doc) On Friday (9th), the FCC issued a document noting the errors in FCC 08-260A (”Unlicensed Operation in the TV Broadcase Bands, Additional Spectrum for Unlicensed devices below 900 MHz and in the 3 GHz Band”).
(pdf) Here’s a link to FCC 08-260 A.
(link) My earlier quicky summary.
(pdf) First the good news. Today, the FCC announced that they were starting a white space fellowship program to help regulators around the world get up to speed on the FCC’s experiences.
Washington, D.C. – Federal Communications Commission Chairman (FCC) Kevin J. Martin today announced the creation of a new International TV White Spaces Fellowship and Training Initiative. The use of TV white spaces has the potential to improve wireless broadband connectivity and inspire an ever-widening array of new Internet-based products and services for consumers. International experts and fellows will have the opportunity to interact directly with FCC staff through in-country interaction, structured educational dialogue, a dedicated interactive website, online training videos, and an annual conference.
Coupled with 802 starting up its study on white-space issues, it looks like things are falling into place for a global standard in the next few years.
(link) Now the potentially really bad news. The Obama team is looking to delay the DTV transition. Here’s the AP story, but I prefer the ranty goodness in this link.
In a letter to key lawmakers Thursday, Obama transition team co-chair John Podesta said the digital transition needs to be delayed largely because the Commerce Department has run out of money for coupons to subsidize digital TV converter boxes for consumers.
Obama officials are also concerned that the government is not doing enough to help Americans – particularly those in rural, poor or minority communities – prepare for and navigate the transition
“With coupons unavailable, support and education insufficient, and the most vulnerable Americans exposed, I urge you to consider a change to the legislatively-mandated cutoff date,” Mr. Podesta wrote.
For technical clarity (for those that don’t know): Analog TV broadcasts (54 MHz – 806 MHz) are (were?) to shut down next month. All broadcasts then switched to DTV in the bands from 54-698 MHz (channels 2-43) and that’s when white-space services (around the DTV transmissions except for channels 3,4, and 37) are (were?) supposed to start.
But if the transition gets delayed, then 1) there’s less spectrum available (as there will be both analog and digital TV signals in band), 2) individual white space device approval / fielding might also have to wait (testing was for detection of DTV and impact to DTV, not analog TV).
This would also screw up the 700 MHz auctions (Verizon and AT&T) as the bands wouldn’t have cleared and a MediaFLO deployment (Qualcomm) and some reallocated public safety spectrum.
(link) On Saturday, Martin spoke out at the Las Vegas Consumer Electronics show against delaying the DRV transition:
I’m concerned about the confusion that could be created,” FCC chairman Kevin Martin said during an on-stage chat at a premier Consumer Electronics Show in Las Vegas.
“We spent a lot of time making sure everyone knows about February 17. What kind of message will that send if we are telling people that is the date and then we don’t do it?”
To answer Martin, the economics term for the kind of message being sent is “regime uncertainty.” Hopefully that’ll get cleared up shortly after the 20th (preferably in a way that keeps the Feb 17th DTV transition date).
(link) Writing for Ars Technica, Julian Simon thinks the DTV delay is being pushed at ClearWire’s behest – basically to muck up Verizon’s LTE deployments to the benefit of ClearWire’s WiMAX networks.
AT&T now supports the delay, but wants compensation. It also appears that they weren’t planning on rolling out as fast as Verizon claims they were going to.
I was just emailed a press release announcing the formation of an industry group to define a protocol (PHY / MAC) for white space data networks.
They hope to have a draft standard for comment available in the first half of 2009.
Since I don’t have an external link, I’ve put the press release below the fold.
Read the rest of this entry »
The government side of white space spectrum got up and running yesterday with the NTIA issuing a request for comment on their phase I (equipment characterization) draft test plan.
The notice is here (pdf) and the draft test plan is here (pdf).
From what I understand the test-bed participants (Adapt4, Adaptrum, BAE, Motorola, SSC, VT) previously commented and this is more generally open. However, comments are currently due by Dec 30, 2008 which would be a problem for most groups. I think that’ll get pushed back.
An overview of the NTIA testbed effort is here.
While I’m mentioning cognitive radio groups starting up, the SDRF White Space Testing Group had its first official meeting a couple weeks ago (unofficial meetings had been going on since mid-summer). Right now it’s focused on developing / documenting use cases for white space (beyond “WiFi on Steroids”). This is primarily intended to help develop testing recommendations for white space devices, but will also probably feed into the 802 ECSG on white space mentioned below, which will also be starting with use cases.
The press release announcement is here.
This is last minute, but I just found out.
There’s a 802 study group on white spaces starting up today. The first telecon/ webex is at 1:00 PM Eastern today (Dec 2). More information (where you can also sign up for the listserv) is here.
There will be telecons every two weeks.
(link) NAB to push Congress to overturn FCC white space ruling (I’m 99.9% certain it won’t be overturned, but it may impact the non-geolocation-enabled devices).
A statement by NAB suggests that the group may be considering asking Congress to either reverse or substantially alter the FCC’s white-space decision. According to NAB, a large number of lawmakers “publicly expressed opposition or concern over the FCC’s proposed white-space action.”
Among the more notable names listed by NAB are House Commerce Committee Chairman John Dingell (D-Mich.), House Ways and Means Committee Chairman Charlie Rangel (D-N.Y.), Sen. Hillary Clinton (D-N.Y.), Sen. Pete Domenici (R-N.M.), and Sen. Chuck Hagel (R-Neb.).
“There was and continues to be immense concern from a large bipartisan group of lawmakers,” Wharton said, “who recognize the important role that free television broadcasting plays in the daily lives of all Americans. Whether it is for emergency information, AMBER Alerts or news and entertainment, free TV is a service used more than eight hours per day by more than 100 million American households.”
(link) A podcast on who will build the white space network. As opposed to, say, DSRC, I don’t think this is as much of a problem for WISP service. Maybe for other use-cases.
(link) However, Clark Howard (more of a personal finance guy, so that’s how broad white space is now) touts white space for free Internet. If that’s the business model, then there will be deployment issues (see muni WiFi).
(link) Clearwire may use white spaces for added capacity. Since that was news to me, here’s a key excerpt:
The vote was passed 5-0 and will allow Google and friends – including Time Warner, Comcast, and Intel – to pour their $3.2bn into the venture and take 22 per cent of the company. That leaves Clearwire shareholders with 27 per cent and Sprint Nextel with a controlling 51 per cent ownership.
But even that infusion of cash isn’t going to be enough to build the 140 million points of presence New Clearwire is expected to need for national coverage. That’s going to set the company back another $2.5bn at least – possibly a lot more, which explains the sudden interest in white space spectrum.
“I think that presents some interesting opportunities for us, and we’ll be looking at how we might leverage it in the rural areas,” said CEO Benjamin Wolff, in a conference call following the filing of Clearwire’s Q3 results, as reported by Information Week. This fits in well with how Motorola sees white-space spectrum being used: medium-distance fixed connections for telco backhaul, rather than the “Wi-Fi on steroids” that some have been promoting.
(link) Making money coming and going (from both the air interface in the preceding and the content via ads), Google said of the expected boost in internet usage by 25-30%. I think that’s a bit high in the near term, but here’s the nut graph.:
Page predicted the free use of white space will boost Internet use so much, his firm’s online ad revenue will rise 20% to 30% a year.
(link) Dell to include white space capabilities in their laptops.
And for more general cognitive radio…
(link) PicoChip looking at cognitive radio for femtocells. It’s not called as such, but:
picoChip Designs Ltd (Bath, England) has released three reference designs for femtocells that deals with one of the major problems and concerns surrounding the emerging technology.The software designs are said to provide the first integrated ‘network listen’ (or ’sniffer’) capabilities for femtocells.
“A femtocell needs to control itself and fit in with its network environment and ensure there is no interference. This diagnostics capability is hugely important for cell planning, synchronization and handover within networks, and these designs provide the algorithms needed for the necessary measurement and reporting information,”, Rupert Baines, VP of marketing at picoChip told EE Times Europe.
The ‘network listen’ functionality also enables the implementation of the self-organizing network (SON) techniques that will underlay the operation of future networks, and can be used to support timing and synchronization.
Baines notes that currently, most of this diagnostics and interference management is supplied by the femtocell OEMs, often using proprietary algorithms and computational techniques.
(link) A brief overview of the E2R effort.
Buried in yesterday’s election returns is a press release noting that the FCC has approved the use of white space devices.
Fcc press release (pdf)
Reuters / Yahoo summary
While I can’t find the actual report and order (FCC 08-260) here’s what I found from the commissioners’ comments and the FCC press release:
- Required detection technique is geolocation (via database access) + sensing
- Will consider lower power detection only devices
- Gelocation database includes registered wireless mic locations (e.g. sporting venues and Broadway)
- Sensing includes requirement to detect both TV and wireless mics
- Operating in channels adjacent to TV broadcasts are allowed if transmit powers < 40 mW
- Higher power levels (??) allowed for nonadjacent channels
- Unlicensed only
- Higher power rural transmissions to be addressed later
- No statement of legal resposibilities of unlicensed interferers
I’ll check again later to see if FCC 08-260 is posted and update this post as needed.
Here’s FCC 08-260: (pdf). Excerpting from the executive summary:
- We are providing for both fixed and personal/portable devices to operate in the TV white spaces on an unlicensed basis.
- All devices, except personal/portable devices operating in client mode, must include a geolocation capability and provisions to access over the Internet a database of protected radio services and the locations and channels that may be used by the unlicensed devices at each location. The unlicensed devices must first access the database to obtain a list of the permitted channels before operating.
- The database will be established and administered by a third party, or parties, to be selected through a public notice process to solicit interested parties.
- Fixed devices may operate on any channel between 2 and 51, except channels 3, 4 and 37, and subject to a number of other conditions such as a restriction against co-channel operation or operation adjacent TV channels pending consideration of further information that may be submitted into the record in this proceeding. Fixed devices may operate at up to 4 Watts EIRP (effective isotropic radiated power).
- Personal portable devices may operate on any unoccupied channel between 21 and 51, except channel 37. Personal portable devices may operate at up to 100 milliwatts of power, except that operation on adjacent channels will be limited to 40 milliwatts
- Fixed and personal/portable devices must also have a capability to sense TV broadcasting and wireless microphone signals as a further means to minimize potential interference. However, for TV broadcasting the database will be the controlling mechanism.
- Wireless microphones will be protected in a variety of ways. The locations where wireless microphones are used, such as entertainment venues and for sporting events, can be registered in the database and will be protected as for other services. In addition, channels from 2 – 20 will be restricted to fixed devices, and we anticipate that many of these channels will remain available for wireless microphones that operate on an itinerant basis. In addition, in 13 major markets where certain channels between 14 and 20 are used for land mobile operations, we will leave 2 channels between 21 and 51 free of new unlicensed devices and therefore available for wireless microphones. Finally, as noted above, we have required that devices also include the ability to listen to the airwaves to sense wireless microphones as an additional measure of protection for these devices.
- Devices must adhere to certain rules to further mitigate the potential interference and to help remedy potential interference should it occur. For example, all fixed devices must register their locations in the database. In addition, fixed devices must transmit identifying information to make it easier to identify them if they are found to interfere. Furthermore, fixed and personal/portable devices operating independently must provide identifying information to the TV bands database. All devices must include adaptable power control so that they use the minimum power necessary to accomplish communications.
- · All white space devices are subject to equipment certification by the FCC Laboratory. The Laboratory will request samples of the devices for testing to ensure that they meet all the pertinent requirements.
- We will permit applications for certification of devices that do not include the geolocation and database access capabilities, and instead rely on spectrum sensing to avoid causing harmful interference, subject to a much more rigorous set of tests by our Laboratory in a process that will be open to the public. These tests will include both laboratory and field tests to fully ensure that such devices meet a “Proof of Performance” standard that they will not cause harmful interference. Under this procedure the Commission will issue a Public Notice seeking comment on the application, as well as test procedures and methodologies. The
- Commission will also issue a Public Notice seeking comment on its recommendations. The decision to grant such an application will then be made at the Commission level.
- The Commission will act promptly to remove any equipment found to be causing harmful interference from the market and will require the responsible parties to take appropriate actions to remedy any interference that may occur.
(link) iTNews (Aussie mag) interviewed Dr Bostian of VT about cognitive radio. Microsoft is also mentioned.
(link) SlashDot also notes the article, where as always, the comments are the most interesting part (particularly if you want a public perspective), e.g.,
“Cognitive radios!?? Oh no you don’t! (Starts adding layers to tin foil hat.)”
(link) The National Cable & Telecommunications Association issued a letter on white space noting potential interference at head ends. They are not arguing against unlicensed white space devices, but would like the following provisions:
- Restrict the operation of portable devices to a maximum of 10 mW and prohibit transmissions in the VHF channels given the high probability of direct pickup interference to TV receivers.
- Prohibit operations, at a minimum, on channels 2- 4.
- Restrict the operation of fixed devices to at least 400 feet from the external walls of residential buildings.
- Prohibit operation of fixed devices in VHF channels.
- Require spectrum coordination before operation of portable devices on channels adjacent to those being received at headends.
Of the suggested methods by which fixed and portable devices might automatically determine channel availability, it appears that auto-location (GPS or equivalent), combined with regular access to a reliable database containing geographically-indexed lists of available channels, has the potential to provide the flexibility and reliability required to protect headend reception.
I’m coming to the conclusion that white spaces will ultimately be licensed. Sure, it’s a late entrant solution, but consider the following from different parties’ perspectives.
1: FCC (ultimately the only opinion that matters)
Their dual missions (more or less) is to increase public utility from spectrum and to maximize revenues for the government . If white spaces are licensed, they will get used (which increases efficiency over current usage, though likely less than unlicensed) and the government should make a bit of money (not easily done with unlicened devices). Further, licensing should provide better mechanisms for addressing interference (via punishment and after-the-fact management ala Nextel) than if the public has it (see Marines + garage door opener); plus these mechanisms would be ones the FCC is used to.
2: Service providers
Selling services over licensed spectrum is a model they know well, so they’ll be quite comfortable with it. Assuming fixed site equipment (ala 802.22), the networks should look a lot like femtocell networks which the service providers should be comfortable with. Now there will clearly be more spectrum in rural environments than urban environments, but rural broadband that’s the rationale for 802.22 and the ostensible rationale for the White Space Alliance.
3: Equipment vendors
They would still get to sell equipment, but now to customers with a clear business model. Plus any equipment sold would be more likely to conform to 802.22 which is virtually complete now, which means they’ll get to start making sales sooner than a yet to be defined standard for “WiFi on steroids”.
4. White space opponents (broadcasters / wireless mic users)
I think a key argument for them against unlicensed use was: “Who do we sue?”. With licensed service provisions, it should be readily apparent who is responsible for interference in different areas and they’ll have deep enough pockets (the service providers) to make it worth while to go after them (which then gives the service providers incentive to not interfere).
5. White space coalition (Google, Microsoft)
Except for perhaps Adaptrum, most of the White space coalition (or alliance or whatever they want to be called these days) are primarily interested in increasing available data bandwidth. They’ll get it with licensing. Motorola and Phillips should still be more than happy by the opportunity to sell femtocell-like white space equipment in a licensed environment.
6. End users
They’ll still get more data than if white space use is disallowed (though perhaps less than unlicensed), plus there will be an easier mechanism to provide for more than just hot-spot coverage (via the service provider infrastructure), which means more coverage than unlicensed.
Thoughts on licensed white spaces
- This would make 802.22 a winning technology as it provides an immediate mechanism for implementing licensed white space access. Heretofore, I thought it might be DoA.
- This should open up a transition to a mobile 802.22 standard.
- Would still be good to not specify exactly what standard (or family of standards) has to be used in the spectrum to allow for usage to evolve.
- Explicit permissions for resale, leasing and subdivision of licenses would be good.
- I would still like to see some additional unlicensed spectrum opened up to let smaller markets bloom.
- It would still be a significant step forward for cognitive radio, just a smaller one.
(link) Shared Spectrum, and Mark McHenry in particular, gets a nice writeup in the WaPo. The politics of unlicensed white space also comes up.
(link) IET Workshop on SDR and Cognitive Radio. It’s in London on the 18th, so I won’t be there. But Keith from CTVR will be. *UPDATE* In the comments, Keith notes that some of the presentations may appear as webcasts at this site.
(link, pdf) On Monday, Oct 27 E3 and the SDR Forum will host a joint workshop on business, exploitation modem architecture, regulation and standardization aspects of SDR and CR. I’m tentatively slotted to give an outbrief on the SDR Forum’s contribution to an ITU report on “Cognitive radio systems in the land mobile service.” (lots of interesting stuff to cover in 30 minutes)
(link) Cognitive radio got some love at the Intel Developers’ Forum. I don’t see the talk in the catalog though.
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