Misunderstandings of WiMAX and Wi-Fi (1)

WiMAX is the interface standard of the 802.11 Ethernet network, just as Wi-Fi is the standard of the Ethernet network. Over the past two years, WiMax has become the most popular specialized Word sink in the wireless network industry.

It may also be one of the most exaggerated and misunderstood technologies in recent years.

The following are common misunderstandings about WiMAX:

WiMAX must have a larger transmission range than Wi-Fi.

WiMAX is faster than Wi-Fi.

WiMAX will compete with Wi-Fi to replace Wi-Fi

WiMAX is safer than Wi-Fi.

WiMAX must have a larger transmission range than Wi-Fi.

WiMAX can be designed to operate in licensed Wireless frequencies or Public Wireless frequencies. As long as the system enterprise has a license for this wireless band, and WiMAX can use more bandwidth, more time periods, and stronger power to send when it is authorized to operate the band. Generally, only wireless ISP enterprises use the WiMAX technology with the authorized bandwidth. Wi-Fi is designed to work only between GHz and 5 GHz in public frequencies. The US Federal Communications Commission (FCC) specifies that the average transmission power of Wi-Fi is between 1 MW and 100 MW. Generally, the transmission power of WiMAX is about 100 KW, so the Wi-Fi power is about one thousandth of WiMAX. A WiMAX base station with a transmission power of 1 million times of the Wi-Fi base station will have a large transmission distance, and naturally there is no doubt.

Although WiMAX with authorized frequencies obviously has a long transmission range, it does not mean that you have to buy a WiMAX base station as long as you have money. You must have an authorized radio band, just like a music station, and a band license to launch radio waves in the air. However, if WiMAX is deployed in an unauthorized frequency band like wi-fi, its transmission advantage will immediately disappear. Wimax and Wi-Fi are both based on wireless band transmission technology, so they are subject to the same physical law. On the contrary, if you enable Wi-Fi to use the authorized bandwidth under the same conditions, Wi-Fi can be as fast as WiMAX. In addition, WiMAX can use newer multi-path technologies. The new pre-n mimo (multi-antenna bidirectional transmission) technology Wi-Fi product also uses this technology.

WiMax is faster than Wi-Fi.

WiMAX advocates often advertise the speed advantage of the technology. Although WiMAX claims the highest speed of 70 mbyte per second, the latest Wi-Fi MIMO theoretically has the highest speed of 108 mbyte per second, and the actual environment also has a speed of 45 Mbps. I can go to the mall to buy a Wi-Fi MIMO base station for home assembly and confirm that the speed is about 45 mbps. However, WiMAX products have not yet appeared. WiMAX technology is also subject to technical issues and physical laws. It is too early to talk about the actual bandwidth of WiMAX.

When building WiMAX, wireless ISP enterprises will also encounter bandwidth competition challenges that other wireless enterprises will face today. The WiMAX system in the authorized frequency band covers a wide range of about dozens of kilometers. The difficulty of building a WiMAX system is a two-blade sword. This is because the wireless coverage is very large, and many users will compete for the same bandwidth at the same time. Even if wireless ISP enterprises use multiple independent channels to operate, there will still be several times more people using Wi-Fi in the same channel. Every wireless ISP company I know, whether it's a wireless microwave company or a 3G mobile company, or a satellite phone company, will also encounter bandwidth competition and QoS (Service Quality) control problems.

If the network latency is between 200 and 2000 milliseconds, it is impossible for this network to use VoIP, video conferencing, online games, or any other real-time applications. Although there have been discussions about adding a QoS mechanism to WiMAX for VoIP, the implementation methods and implementation benefits still need to be observed. In terms of Wi-Fi, the effectiveness of QoS implementation on Spectralink has been confirmed, and 802.11e wireless QoS standards will also be released. The establishment of WiMAX in wireless ISP enterprises will be slower than that in non-authorized WiMAX or Wi-Fi base stations, because it is impossible for wireless ISP enterprises to allow a few users to use the entire frequency band.

The private WiMAX base stations that use public frequencies, and the setting of Wi-Fi base stations will depend on the launch of the product. In theory, their transmission power is roughly the same as the frequency band, and there are already a large number of mature Wi-Fi products on the market. I personally bet on the Wi-Fi side to win. Wi-Fi has taken a long lead in the non-authorized frequency band, and it is hard to imagine that WiMAX can succeed in this field. This is why WiMAX is mostly promoted to wireless ISP enterprises.