FH/DS Co-existence
Last Post: March 21, 2005:
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I am currently validating a proposal for a WLAN switch implementation co-existing with Frequency Hopping (FH) access points ('proposed' converted to 'access ports') to protect the investment of a large number of FH client terminals throughout the environment. There is apparently a site in the US where this has been done successfully. Out of interest, has anyone heard of this, seen it done or worked on such a solution out there?
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I have not heard of, seen, or worked on FH coexistence with a WLAN switch architecture.
From a theoretical perspective limiting the overlay WLAN switch to 5GHz OFDM (802.11a) would be entirely compatible with a 2.4GHz FHSS system.
HR/DSSS has a channel agility feature to allow it to interoperate with FHSS systems, but I am unaware of anyone ever building channel agility into a chip set.
I hope this helps, even a little. Thanks. /criss -
Hi,
we just work on the same thing...
We tested the coexistence between 3 Symbol AP3121 and 3 Cisco AP1231 (Channels 1, 6 and 11) and many mixed mobile devices (several Symbol PDTs and Cisco PCMCIA)
There were no abnormal effects or influences noticeable. All roaming features worked as awaited and the data troughput was absolutely acceptable (for barcode capturing). It seems, that we will have more complexity related problems at the customer site with more than 3 or 4 APs on the same channel seen at one place (as usual;)
I will post a second time when we have finished our installation.
Regards from Germany... -
...sorry, i forgot to tell you, that this is our first step for migration from FH to DS. Next step will be the installation of the WS5100 from Symbol an adopt (some of) the old FH AccessPoints as AccessPorts.
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Hi siebertl of Bavaria:
IEEE 802.11 access points I know. Please what is the vendor's definition of an AccessPort?
Thanks. /criss -
Hi Mark,
...an Access Point is a "Network Edge" with all the logical stuff inside so you can reach it e.g. via Layer 3 or 4 (TCP/IP)...
... but an AccessPort has nothing of this - it is a dumb antenna, i would say - and you need a centralized Wireless Switch to manage the Access Port and use it as a "Network Edge" ... (the advantage is, that you have no more work to do on each AccessPoint like manage WEP Keys, IP Addresses, LogFiles, ... and if you want to have an extension of your Network, you only have to add a new AccessPort and allow it to work centralized from the Switch - thats all) - i like it!
Kind regards from the sunny Bavaria ;-) -
Hi Siebertl of Bavaria:
Thanks for the information. I am not acquainted with the Symbol product line.
What you describe sounds like what many people call fat and thin access points. The fat ones are full of features that allow them to be used absent a centralized management platform. The thin ones are void of features that allow them to be used absent a centralized management platform.
Because both fat and thin access points typically use an IP layer for management I would not call a thin one a dumb antenna. "Dumb" access point doesn't sound marketable either. ;-D I also like the thin concept.
I hope this helps. Thanks. /criss
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