Friday, 3 February 2012

Understanding Some Frequency Auction Terms

Industry Canada is scheduled to announce ‘soon’ the details on how the auction of the 700 MHz spectrum will be conducted. (Note: ‘Soon’ is used in the sense of government time – not the real world.)

Mobile vendors in Canada have been anxious to gain access to this spectrum which was freed up due to the transition from analogue to digital television signals last year.

In addition to giving relief to the vendors, the technical characteristics of the 700 MHz band mean the signal is able to travel farther, bend more to follow the curvature of the earth, and penetrate structures and foliage better creating improved indoor reception. This means vendors will require fewer towers to cover a greater area. It is also the preferred frequency for LTE service.

This blog is a review of some terminology which may be heard during the auction.

The radio frequency spectrum is divided into a number of Bands. (Note: The term “band” is often used to identify various aspects of the radio frequency spectrum so the term must be read in context.)

This chart shows the frequency bands.


All Mobile phone and most fixed wireless broadband (high speed) Internet is located in the Ultra High Frequency (UHF) band identified as the range: - 300 MHz to 3 GHz with a wavelength of 1m to 10cm.
Within the UHF band, one often sees reference to Mobile phones and antennae operating in the 800 MHz band, 850 MHz band, 1700 MHz band. 1900 MHz band, 2100 MHz band and so on. Use number two of the word “band”. These frequencies are agreed by international conventions. You can search for “3GPP TS 45.005” if you are interested on all the gory details.

During frequency auctions, each of these bands is further divided into frequency blocks, usually identified by letters A to ?. The blocks are defined by the national authority but with due consideration to international conditions. The blocks are then further divided into bands based on the bandwidth measured in Hz. Use number three of the word “band”.

Since the US did their TV conversion to digital a number of years ago, we can look at how they handled the spectrum to see how these terms noted above are applied and perhaps help understand the Canadian rules when they are announced.

Frequency Spectrum
700 MHz Band
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AWS = Advanced Wireless Services. In Canada the new services like WIND, Mobilicity, etc. are in this category
PCS = Personal Communications Service. In Canada Fido is the best known PCS. The term is seldom used any more.

The US conducted two separate auctions over a number of years and this resulted in the Lower 700 (2002) and Upper 700 (2008) split.

The auctions divided the UHF spectrum into 5 blocks with paired bands in most cases. Paired bands means one band is used for transmit and the other band for receive. Only Block E in 2002 was an unpaired band.
    • § Block A: 12 MHz bandwidth (698–704 and 728–734 MHz)
    • § Block B: 12 MHz bandwidth (704–710 and 734–740 MHz)
    • § Block C: 22 MHz bandwidth (746–757 and 776–787 MHz)
    • § Block D: 10 MHz bandwidth (758–763 and 788–793 MHz)
    • § Block E: 6 MHz bandwidth (722–728 MHz)
(There is a Canada–US-Mexico agreement on coordinated use of the 698-758 MHz and 776-788 MHz frequencies within 120 km of the respective border regions. )

In the Upper 700, the C block is a full 22 MHz wide, compared to 12 MHz for the other major blocks. That extra bandwidth means extra capacity, for handling more voice calls and/or more data.

In additional to the technical details, the auction also established geographical areas for where the frequencies can be used. In the end the two big winners were Verizon and AT&T with Verizon getting all the most valuable Block C 22 MHz coverage.

Verizon 700 MHZ Coverage
AT&T 700 MHZ Coverage
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Notice that the Verizon bands (frequencies) are not compatible with AT&T bands. Nor is the coverage. In the US experience, this is beginning to create problems and a backlash from smaller vendors. I will look at this issue in another blog.

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