Generally, there are several differeces between WiFi and WiMax:
1. The coverage.
When operating in the licensed band, WiMax can use more bandwidth, more transmission power for broadcast. While WiFi works on unlicensed band from 2.4GHz to 5GHz, with transmission power of 1 mW to 100mW which is stipulated by FCC. Compared with the power of WiMax - 100 kW, the coverage of WiFi obviously can not catch up with WiMax. But there is a premise, i.e. the licensed band. If in the public band, the advantages of WiMax will disappear immediately.
2. The speed.
It was claimed that WiMax can reach up to 70 MB/s, but the lasted WiFi MIMO (Multi-input and Multi-output) can theoretically reach up to 108 MB/s, the practical rate is 45 MB/s. Anyone can go to the market and bring home a base station , seting the speed at 45 MB/s himself, while the product of WiMax is still unavailable in the market, so it is too early for the discussion on the speed of WiMax.
3. The competition for bandwith
Theoretically, WiMax has a wide coverage which spreads to tens of miles, it leads to much more users competing in the same bandwidth, turning out a relatively longer delay. WiFi, In comparision with WiMax, has less users because of its smaller coverage, which makes it react faster and suitable for VoIP, video conference, Internet game and other real-time applications.
In my opinion, WiMax is better for worldwide coverage of wireless communication, while WiFi is suitable for the applications in a small range such as office or home wireless networks.
To choose from the two technologies, it should be based on different situations.WiFi provides a connection within a limited area, such as home or office. WiMax is used to provide a broadband connectivity from a center location with a radiation radius like a mobile phone service. So WiMax can be used even when moving at high speed and it may have some dead spots in building.
WiMax has much greater range than WiFi, and also has some benefits over WiFi in terms of connection quality. As for WiFi, too many users will lead to inadequate bandwidth, while Wimax can automatically redirects additional users to another Wimax access point.
Though WiMax is much more flexible and easier to configure than WiFi, so far WiFi is more widely deployed than WiMax because WiFi is more mature in the market. It is too early to decide which one we could choose.
