All three channels are 802.11g or 802.11b or any combination thereof.
Each channel is independent and can be configured by software to be a/b or g......although the a flavor requires a different RF chip (Engim has both a 2.4 GHz transceiver chip and a 5.2 GHz transceiver chip each capable of handling 3 channels.
Halvard you ar mistaken.
actually the 2.4 GHz to 2.484 GHz band is unlicensed by the FCC.
This means that any device can use this band as long as the transmitted power is below 1 watt AND the emissions in the restricted bands (a set of defined freqeuncy bands) is lower than the prescribed power levels (see FCC rules part 15)
Any device using the 2.4 GHz to 2.484 GHz band MUST accept interference from any other device using this band. It is up to the people that are setting up the equipment to make sure it works without interfering with existing equiment.
this mean the FCC will not be policing the usage of these frequencies. once you are outed you will have to work it out with your neighbors your self.
27 MBPS is the maximu data thruput you will get from 802.11g @ 54 MBPS. bulls--t someone says
well consider that the 54 MBPS is the absolute maximum data rate that infomation can be sent over the 802.11g channel. So in one second 54 million bits can be transfered from one user to another. But not all of those bits are actually data being transfered. Some of the bits are used to tell all the airwave users how the AP (if there is one) is setup. Remember to communicate over a link all the users (at least the sucessfull ones) must speak the same language. so some of the bits are used to tell all of the users waht language to use (beacons). In 802.11 all communication between users are are done in packets of data, all packets are acknowledged (ack packets) by the receiver on proper receiption. The time it take to send the acknowlement packets uses up some more of the bits. There is also short gaps between the packet and the ACK packet where no data is sent, more bits lost from the actual thruput.
All packets are preceeded by a header that contains information to allow the receiver to synchronize with the incoming packet and properly decode the packet bitstream. the header also contains a bunch of bits that describe the packet's properties ie. length, modulation, source address , destination address...
this header also take time and uses up even more of the bits.
for fair use of the airwaved channel each transmiter is required to wait a random time interval after the reception of an ACK packet before transmiiting. this results in quiet times when no one is transmitting. thus more lost bits that don't count towards thruput.
when one looks at all these lost bits over the full second time interval one finds that they total at least 27 million bits. thus the maximum theoretical thruput is 54 - 27 = 27 million bits
ie 27 MBPS.
thus if you are getting 25 MBPS thruput on your 802.11g network congrats you are getting just over 92% of the rated capacity!!!!
BTW 80% would be 21.6 MBPS not too shabby
engimeer
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All three channels are 802.11g or 802.11b or any combination thereof. Each channel is independent and can be configured by software to be a/b or g ......although the a flavor requires a different RF chip (Engim has both a 2.4 GHz transceiver chip and a 5.2 GHz transceiver chip each capable of handling 3 channels.
Halvard you ar mistaken. actually the 2.4 GHz to 2.484 GHz band is unlicensed by the FCC. This means that any device can use this band as long as the transmitted power is below 1 watt AND the emissions in the restricted bands (a set of defined freqeuncy bands) is lower than the prescribed power levels (see FCC rules part 15) Any device using the 2.4 GHz to 2.484 GHz band MUST accept interference from any other device using this band. It is up to the people that are setting up the equipment to make sure it works without interfering with existing equiment. this mean the FCC will not be policing the usage of these frequencies. once you are outed you will have to work it out with your neighbors your self.
27 MBPS is the maximu data thruput you will get from 802.11g @ 54 MBPS. bulls--t someone says well consider that the 54 MBPS is the absolute maximum data rate that infomation can be sent over the 802.11g channel. So in one second 54 million bits can be transfered from one user to another. But not all of those bits are actually data being transfered. Some of the bits are used to tell all the airwave users how the AP (if there is one) is setup. Remember to communicate over a link all the users (at least the sucessfull ones) must speak the same language. so some of the bits are used to tell all of the users waht language to use (beacons). In 802.11 all communication between users are are done in packets of data, all packets are acknowledged (ack packets) by the receiver on proper receiption. The time it take to send the acknowlement packets uses up some more of the bits. There is also short gaps between the packet and the ACK packet where no data is sent, more bits lost from the actual thruput. All packets are preceeded by a header that contains information to allow the receiver to synchronize with the incoming packet and properly decode the packet bitstream. the header also contains a bunch of bits that describe the packet's properties ie. length, modulation, source address , destination address... this header also take time and uses up even more of the bits. for fair use of the airwaved channel each transmiter is required to wait a random time interval after the reception of an ACK packet before transmiiting. this results in quiet times when no one is transmitting. thus more lost bits that don't count towards thruput. when one looks at all these lost bits over the full second time interval one finds that they total at least 27 million bits. thus the maximum theoretical thruput is 54 - 27 = 27 million bits ie 27 MBPS. thus if you are getting 25 MBPS thruput on your 802.11g network congrats you are getting just over 92% of the rated capacity!!!! BTW 80% would be 21.6 MBPS not too shabby engimeer