Showing posts with label software defined radio. Show all posts
Showing posts with label software defined radio. Show all posts

Sunday, November 16, 2008

"White Spaces" Rules for TV Spectrum Released

On Friday (11/14/2008) the Federal Communications Commission (FCC) released their long-awaited and highly-debated Rules for the development and operation of so-called television band "white spaces" devices to be authorized under CFR 47 Part 15 sub-part H.


The following is excerpted from the FCC's "White Spaces" Order (FCC 08-260) on ET Docket No. 04-186 and ET Docket No. 02-380):


Introduction - Item 10. All Devices. All unlicensed TV band fixed and personal/portable TV band devices will be permitted to operate on TV channels 21-51, excluding channel 37. In addition, fixed TVBDs that only communicate with other fixed TVBDs will be permitted to operate on channels 2 and 5-20, except that they must avoid operation on channels used by private land mobile radio service (PLMRS), i.e., public safety, and commercial mobile radio service operations on channels in certain markets and areas adjacent to them. Also, in individual markets where there are Private Land Mobile Radio Service or Commercial Mobile Radio Service (PLMRS/CMRS) operations on channels 14-20, two channels in the range 21-51 will be reserved for operation by wireless microphones such that TVBDs will not be permitted on those channels. This plan for channel use is consistent with the requests of the various white space proponents and would reserve channels for a "safe harbor" for operation of wireless microphones and ensure protection of the public safety and other land mobile services that use channels 14-20. At this time, we are only permitting fixed TVBDs to operate on channels not that are not immediately next to (first adjacent on either side of) the channel of a TV station; personal portable devices will be allowed to operate on first adjacent channels to a TV station subject to the power limitation indicated above. All unlicensed TV band devices will be required to limit their out-of-band emissions in the first adjacent channel to a level 55 dB below the power level in the channel they occupy, as measured in a 100 kHz bandwidth. In addition, all TVBDs will be required to comply with a more stringent out-of-band emissions band at the edges of channels 36 and 38 that are adjacent to channel 37 in order to protect medical telemetry devices on that channel 37. Fixed devices will also be required to periodically transmit a signal with their identification when they are operating. This will facilitate identification of sources of interference. The database system for fixed stations and personal/portable devices with geo-location and database access capability will be managed by a database manager or managers selected by our Office of Engineering and Technology.


Full text of Order:

http://hraunfoss.fcc.gov/edocs_public/attachmatch/FCC-08-260A1.pdf


It'll be at least a year or more until any products or services are available to utilize this spectrum (none have been certificated by the FCC as yet and, you can probably count on both proponents and opponents continuing their war of words and legal challenges), so, this might be a good time to suggest that all potential "white spaces" users familiarize themselves with Appendix B of the Order which contains the Final "White Spaces" Rules and the new Part 15 Sub-Part H on Television Band Devices.


NR

Wednesday, March 26, 2008

The Great "White Spaces" Challenge

Google (and its technology partners) are facing the great "white spaces" challenge - the next big spectrum allocation battle - from the politically powerful NAB (National Association of Broadcasters) and others.

On the one hand we have the over-the-air TV broadcasters (who rarely offer much worth the bandwidth it takes to beam it into our living rooms) insisting that the spectrum will "suffer" from the use of unlicensed wi-fi like devices operating near THEIR frequencies.


On the other hand, we have pretty much the rest of the country clamoring - no, make that screaming - for the opportunity to deploy "innovative" wireless communications devices and services, "stimulate" our economy, and make "better use" of nearly the very SAME spectrum - all on an unlicensed basis with little if any regulatory enforcement of that use. (Which, IMHO, is a somewhat worrisome scenario to begin with considering the historical track record over the years of the FCC's ability to "protect" the natural resource we call the RF spectrum, AND, the purported "better use" and "innovation" that the "white spaces" proponents claim they'll make with the resource.)


This spectrum battle should prove VERY interesting to say the least. Let's hope the regulators make the right decision - whatever "right" is deemed to be these days.



NR
(Repost)


Monday, December 10, 2007

SDR, CR, DSA, & the 700 MHz Public Safety Band

The folks at the SDR Forum have released a new 23 page report addressing "Considerations and Recommendations for Software Defined Radio Technologies for the 700 MHz Public/Private Partnership" (Technology for 700 MHz Spectrum - Report # SDRF-07-R-0024-V1.0.0) just in time for review prior to the upcoming FCC auction.

Here's a summary:


The report describes how software defined radio (SDR) technologies can help achieve the public/private partnership goals of the upcoming U.S. FCC 700 MHz frequency band spectrum auction. This report also covers cognitive radio (CR) and dynamic spectrum access (DSA) technologies as well.


The context for the report is the Second Report and Order (FCC 07-132, released 10 August 2007) which establishes rules governing wireless licenses in the 700 MHz band. The SDR Forum
is uniquely positioned to consider the role of these new technologies in the 700 MHz band since its membership includes commercial mobile radio service providers, public safety representatives, technology developers, systems integrators and equipment manufacturers.

The information and recommendations in the report focusus on technology and related policy
considerations to (a) prospective bidders and service providers, (b) potential grantees of the Public Safety Broadband License, (c) equipment manufacturers, and (d) regulators.

Emerging SDR & CR technologies, along with DSA (
or DSM - Dynamic Spectrum Management) are believed to be the future of wireless communications.

The report is well worth the time to read for those interested or concerned with spectrum matters.



NR

(Repost)


Saturday, October 13, 2007

Managing "Open Access", "White Spaces", & Unlicensed Spectrum

There's more than a few issues and challenges open for consideration and debate when it comes to allowing more and more "open access" and license-free use of the radio spectrum as the authors of this 2005 white paper attempt to point out....

"Managing Shared Access to a Spectrum Commons"
(Presented at the IEEE DySpan2005 - Baltimore - November 2005 By William Lehr and Jon Crowcroft)

Abstract


The open access, unlicensed or spectrum commons approach to managing shared access to RF spectrum offers many attractive benefits, especially when implemented in conjunction with and as a complement to a regime of market-based, flexible use, tradable licensed spectrum.


However, as a number of critics have pointed out, implementing the unlicensed model poses difficult challenges that have not been well-addressed yet by commons advocates.


A successful spectrum commons will not be unregulated, but it also need not be command & control by another name. This paper seeks to address some of the implementation challenges associated with managing a spectrum commons. We focus on the minimal set of features that we believe a suitable management protocol, etiquette, or framework for a spectrum commons will need to incorporate.


This includes: (1) No transmit only devices; (2) Power restrictions; (3) Common channel signaling; (4) Mechanism for handling congestion and allocating resources among users/uses in times of congestion; (5) Mechanism to support enforcement (e.g., established procedures to verify protocol is in conformance); (6) Mechanism to support reversibility of policy; and (7) Protection for privacy and security.


We explain why each is necessary, examine their implications for current policy, and suggest ways in which they might be implemented.
We present a framework that suggests a set of design principles for the protocols that will govern a successful commons management regime. Our design rules lead us to conclude that the appropriate Protocols for a Commons will need to be more liquid than in the past: (1) Market-based instead of C&C; (2) Decentralized/distributed; and, (3) Adaptive and flexible (Anonymous, distributed, decentralized, and locally responsive).


Offered as suggested background reading and insight in light of the big push for these by the TV "white spaces" proponents, the Cognitive Radio/SDR folks, and the Google's, Intel's, and Microsoft's of the new wireless world.



NR

Saturday, September 15, 2007

Dynamic Spectrum Management (DSM) - Regulatory & Allocation Method of the Future?

Radio (RF) spectrum is key to the future success of (wireless) radiocommunications. It is a valuable commodity and a unique, shared resource. Unlike other natural resources, it can be repeatedly reused - if certain technical conditions are met and user regulations are followed.

In practice though, it is a finite resource, accommodates a limited number of simultaneous users, and requires careful planning and management to maximize its value for all services and users
— especially since worldwide demand for communication spectrum is increasing rapidly.

Many new wireless technologies present significant challenges to the development of prudent business models as well as to long-established regulatory schemes for spectrum allocation and management.

Rigid spectrum allocation policies limit innovation and cannot readily accommodate pressing needs for more commercial bandwidth.
Operators look to evolve technologies that support their business cases. Licensing or policy making that would not allow this natural evolution or mandate a particular technology in a particular band is too rigid for many operators. New generation infrastructure and terminals must support ever wider ranges of frequencies, harmonized or not, to meet highly heterogeneous frequency plans in markets around the world. Terminals will need to operate worldwide and comply with numerous regulatory environments and market opportunities, thus supporting frequency allocation and heterogeneous technologies. New technologies such as software-defined radio (SDR) or cognitive radio (CR), wideband power amplifiers and filters are already available in the infrastructure and will soon be available in terminals, supporting frequency heterogeneity with minimal additional cost.

Within this context, traditional ways to assess the merits of new technical solutions, and
allocate and tax frequency use are inadequate. Consequently, this presents major challenges in the introduction of new technologies and efficient spectrum use, such as ensuring new spectrum is only assigned when really needed.

This 2006 Alcatel-Lucent white paper describes a new concept known as DSM (Dynamic Spectrum Management) which would enable wireless operators to dynamically access appropriate spectrum to deliver new wireless services, while providing greater choices for spectrum users. It provides an overview of DSM from the engineering, technology, economic and radio policy aspects and considers critical parameters that impact its implementation.


The paper should be required reading for anyone involved with or concerned about current methods of spectrum regulation and allocation in the U.S., and, perhaps even more importantly, with how any spectrum management methods chosen will ultimately serve to protect this resource from eventual political and economic oversell.



NR