Wireless technologies are also divided into different types, usually in the form of wireless signals. Currently, the main methods are FM wireless technology, infrared wireless technology and Bluetooth wireless technology, and their cost and characteristics are not the same. Widely used in audio, mouse and mouse and other content, has a good development prospects.
In recent years, with the popularity of light and broadband, people's lives have become more and more closely linked to the Internet. At present, many families have one or several personal computers. In addition to laptops and traditional desktop computers, how to easily and conveniently connect these different devices to the Internet. WiFi technology is highlighted by its own characteristics, and it has become the primary choice for most homes and multiple devices to access the Internet.
First, the technical characteristics of WiFi
1.1 Advantages (1) The radio wave coverage is wide, and the WiFi radius is up to 100 meters, which is suitable for use on the unit floor and the office. Bluetooth technology only covers less than 15 meters.
(2) Speed ​​is not only fast, but also high reliability
The 802.11b wireless network specification is a variant of the IEEE 802.11 network specification. The maximum bandwidth is 11Mbps. When the signal is interfered or weak, the bandwidth can be adjusted to 1Mbps, 5.5Mbps and 2Mbps. The bandwidth is automatically adjusted to ensure the reliability and stability of the network.
(3) No wiring required
The advantage of WiFi is that it does not require wiring and is not limited by the wiring conditions. Therefore, it is very suitable for mobile office users and has a broad market prospect. Today, wifi has expanded from a special industry such as inventory control, traditional healthcare and management services to a wider range of industries, and even into educational institutions and homes.
(5) Health and safety
The transmit power set by IEEE802.11 cannot exceed 100 mW, and the actual transmit power is about 60-70 mW. The mobile phone's transmitting power is about 200 milliwatts to 1 watt, and the handheld walkie-talkie is up to 5 watts. The wireless network is not used in such a way that the mobile phone directly contacts the human body and has certain security.
Second, the shortcomings The IP wireless network currently used has some shortcomings, such as long switching time, small coverage radius, low bandwidth, etc., so it can not support mobile VoIP and other high-demand applications. Because the wireless network system does not open up the upper-layer business development, many businesses suitable for the IP mobile environment are difficult to develop. WLAN products that are located in home users cannot meet the requirements of operators for network maintenance and operation in many places.
Third, wifi security
Under the premise that wifi provides a large number of applications, network security is a problem worthy of our attention. On the one hand: wifi gives us a lot of ways to access the internet. Let us have unlimited resources of the Internet; on the other hand: wifi also brings us a lot of security issues, all kinds of hackers, viruses, attacks, etc. have threatened our online transactions at any time.
3.1 wifi has security risks
The security risks of wifi come from two aspects: on the one hand, it is an "attack" from the network. On the other hand, it comes from the "trap" of the network. The security risks of wifi are mainly: (1) malicious phishing AP; (2) access attack; (3) Dos and DDos attack.
3.2 wifi security mechanism
Wifi has a lot of security issues, but it does not affect our love of Wifi, through a series of security mechanisms to solve online security problems. It mainly includes two parts: network encryption and access control. That is, network encryption can only understand the data content if only the correct recipient can decrypt it. Access control only allows users to access network data through Wifi.
(1) WPA technology is a wireless network-based usage protocol. WPA provides users with access to the internet network to provide data protection through authorization. Therefore, users who are not authorized cannot access data.
(2) Encryption technology. The encryption methods used on today's networks are mainly AES and TKIP.
Journal article classification query, in the journal library (3) authentication technology, Wifi Internet security authentication method can ensure the security of user access data, its main certifications are: Web authentication, wireless access authentication, PPPoE authentication.
Fourth, the application of WiFi technology
4.1 Wireless Internet Because the frequency band of WiFi does not require any free band of telecom operation licenses worldwide, WLAN wireless devices are available worldwide. The wireless air interface is not only inexpensive, but also has a very high data bandwidth. Users can quickly browse the web within the WiFi coverage area and answer and make calls anytime, anywhere. Other WLAN-based broadband data usage, such as online games, streaming media and other features are worthy of user expectations. Since the advent of WiFi, we have been browsing the web, downloading music, making long distance calls, digital photo delivery, sending and receiving emails, etc., so we don't have to worry about the high cost and slow speed.
4.2 Pocket Device WiFi Application WiFi applications are becoming more and more popular on handheld devices, and smartphones are one of them. Unlike previous Bluetooth technology used on mobile phones, WiFi has a higher transmission rate and greater coverage, so WiFi mobile phones have become the fashion trend of today's mobile communications industry. Users can not only browse the web quickly, but also answer and make calls anytime, anywhere within the WiFi coverage area. Other parts of the WLAN-based broadband data use, such as: online games, streaming media and other functions are more worthy of user expectations. Nowadays, there are WiFi interfaces in luxury residential areas, high-end hotels, cafes and airports in many cities around the world.
When we go to various meetings, parties, and tours, we can use our handheld devices to surf the Internet in these places. With the advent of the 3G era, more and more telecom operators are turning their attention to WiFi technology. The 3G coverage is low and the bandwidth is low. Both technologies have the opposite advantages and disadvantages. WiFi technology wireless, high-speed, low-cost features are very suitable for the use of the 3G era. In terms of mobile phone 3G services, smartphones that now support WIFI can easily browse the Internet through APs. With the development of VOIP software, VOIP software represented by Skype has been able to support a wide variety of operating systems. After the corresponding VOIP software is installed on the smart phone equipped with the WIFI module, the voice communication can be realized through the WiFi network technology.
Fifth, the development trend and prospects of wifi
WiFi is the mainstream standard for wireless access today, but how far can WiFi go? Currently, wifi has a successor - WiMax. Wifi is fully compatible with WiMax, and its standard is 802.16x. WiMAX has a wider band selection, higher access speeds, and longer transmission distances. However, there are still some differences between WiMax and wifi. The two standards are different and are not in the same category. WiMax is mainly used in the wireless metropolitan area network. WiFi is mainly used in the wireless LAN category. There is a complementary competition between the two, and there is no substitute relationship. WiFi is more suitable for use in urban areas, and WiMax is more suitable for outdoor use in urban areas. Wifi can play an important complementary role to 3G in a specific range and area. It is undeniable that commercial wifi technology has encountered some problems that need to be solved.
On the one hand, it is subject to the limitations of wifi technology, such as security, how to bill, and roaming. On the other hand, because the profit model of wifi is not clear, such as the operation of wifi as a single network, the shortage of commercial users will make the investment income of network construction lower, which also greatly affects the enthusiasm of telecom operators. However, from the perspective of wifi technology positioning, wifi technology is still a good complement to mobile cellular networks. It is believed that with the integration and continuous development of wifi technology and other related technologies, there will be a broader development prospect. In the era of rapid network development, people have already tasted the convenience that WiFi brings to us. We firmly believe that the convergence of 3G and WiFi will definitely open a new era of communication for us.
Conclusion:
More and more restaurants, hotels, airports and other places have begun to provide WiFi conditions, and the three major operators are deploying WiFi hotspots on a large scale. With its own characteristics, WiFi has expanded its reach to the Internet of Things and medical fields, and people's lives will change due to WiFi.
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