• Still about WiGig backwards compatibility.

    According to the press release by the Wi-Fi Alliance:

    [i]The WiGig specification defines protocols to deliver data transfer rates measured in gigabits rather than megabits and supports a new range of applications and usages. The specification also defines procedures to enable WiGig-compliant devices to hand over sessions to operate in the 2.4 or 5 GHz band. It is expected that a new class of [b]tri-band Wi-Fi CERTIFIED devices[/b] will offer multi-gigabit wireless speeds while helping to ensure backward compatibility.[/i]

    My assumption: The WiGig-compliant devices are capable of operating on 2.4, 5 or 60 GHz frequency bands. If a 'pure' WiGig environment - only WiGig APs and STAs are used, no legacy 802.11 radios - exists, the network will operate on 60 GHz band and the maximum data rate of 7 Gbps can be achieved.

    If the network sees any 802.11a, b, g, or n devices, however, it will switch to the related frequency band(s). For example, if an 802.11g STA enters a WiGig AP-enabled network, the AP will decide to operate on 2.4 GHz instead of 60 GHz band.

    Can I draw an analogy between WiGig backwards compatibility and 802.11n protection mechanism? Of course, the real issue is complicated. How about a mix environment with 802.11a/b/g/n and WiGig radios? What data rate(s) will be achieved in this case?

  • The issue with that would be that the signal propogation properties of WiGig would be considerably less than those of 2.4 or 5.0 Ghz therefore I anticipate that it would not be analogous to protection mechanisms but actually incorporate seperate radios to support all technologies.

    However I would anticipate that WiGig applications would be considerably shorter range and as such does not currently fit the distributed architecture that we use for wireless deployments today.

    Just my 2 cents

  • Dave,

    You mentioned the cell phone usage. Have you heard of the following statement: it is not a good idea to answer the phone call immediately following the ring, because the electromagnetic radiation during the first 7 seconds is considerably significant.

    The WiGig end products will no doubt conform to the safety/heath standards, but it is still interesting to read more about the operation mechanism of 60 GHz devices.

  • Haven't actually heard of that one. If you hold the phone even a short distance away from your head it can cut down on the amount of energy passing through the skull [ especially the eyes ]. Headsets are good too.
    If you have a spectrum analyzer that covers cell frequencies, you can get a surprise as to how much "juice" is produced by a cell phone.


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