What are the different ways to utilize the channels to get maximum throughput? Is it possible despite interchannel interference?
only few channels are used for communication out of all 16 in ZigBee.
It is not like that all 16 channels are available for Zigbee Devices. Since 802.15.4 uses 2.4 and 5 Ghz band, which is ISM band and is free for the use of many devices including 801.11 and 802.15.6 (Body Area Network). Therefore, all the devices which use ISM band (specially free spectrum, unlike mobile service which is licensed), are mandatory to implent a coexisting mechnism in such a way so that they should not allow interferce to each other. Even the microwave oven uses the same spectrum.
So, any Zigbee device should first scan all the cahnnels and select a channel with minimum interfernce to form the network. In case of 802.15.4 devices it is PAN coordinator who forms the channel.
Moreover, since 802.15.4 devices are supposed to be having very limited resource and the data transmission requirement is in few bytes, improving the channel utilization by aggregating multiple channels is not the requirement of such device.
My suggestion to you is to re-look the requirement that why 802.15.4 devices need that much bandwidth. There is a class of applications defined by ZigBee consoritum, you can look at and find out the aplications which really demand high data rate.
A small correction of Ashutosh, as far as I know 802.15.4 does not have a physical layer for 5GHz. Yet, there are some channels in the 868/915 MHz ISM bands. Channels 11-26 are in the 2.4GHz band, but there are also channels 0-10.
But it's true that those channels are shared for all devices, and the protocols must be designed that they can avoid co-channel interference.
It is also interesting to note that packets can collide and you may still receive some or even all of the packets. You can have a look at my recent work on this:
https://www.researchgate.net/publication/256762611_An_Analytical_Model_of_Packet_Collisions_in_IEEE_802.15.4_Wireless_Networks
Article On the Reception of Concurrent Transmissions in Wireless Sen...
Though energy efficiency is the primary concern while designing such applications but still some applications like Body monitoring will need more data rate.
I have implemented Zigbee on my system but I have seen only one channel ie channel no 11 is used for communication. Though it is scanning channels 11,12 nd 13. Also i need a brief information regarding how multiple channels are allocated for the communication of different different nodes.
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