Wireless LAN and ADSL Integration Technology

With the continuous development of broadband applications, ADSL is becoming increasingly popular. At the same time, with the emergence and development of wireless LAN technology, this market is also rapidly increasing, but the absolute number is still less than that of ADSL.

At present, technologies and products that combine the two have emerged. The emergence of these technologies will greatly accelerate the popularization of WLAN.

In traditional WLAN Access, an AP acts as an access point, and the AP and wireless network adapter use 802.11a, B, or g as the standard communication, AP serves only as a transparent bridge from a wireless LAN to a LAN. It can only connect users to a LAN. It has no routing function, an additional WAN router is required to connect users to the Internet. Therefore, it is mainly used in enterprise intranets.

Traditional AP generally has no routing function and is completely a layer-2 device. With the needs of home and SOHO offices, the AP with routing function appears. AP with routing function can not only achieve WLAN access, but also provide WAN interface, with three-layer IP routing and Network Address Translation NAT functions, you can access the Internet through ADSL/MODEM/FTTB + LAN and other technologies. In addition, some products also provide four Ethernet switches and print interfaces as printing servers. Some high-end devices can also integrate VPN functions, therefore, the cost is much lower than that of the "AP + Router" network, and the network structure is relatively simple. It is suitable for small networks or home networks.

The AP router with ADSL interfaces is developed on the basis of the AP with routing. The WAN interface of the AP is changed to fixed ADSL, which is more economical than the AP with the routing function and the ADSL modem, management is more convenient, thus realizing the integration of ADSL + WLAN.

The AP router system with ADSL interfaces is mainly composed of four parts: the network processor, which implements data packet distribution, media conversion, routing/NAT, system control, and other functions; the ADSL part, responsible for ADSL line transmission and receiving, DMT modulation and other functions; wireless part, responsible for wireless signal modulation, transmission and receiving; Ethernet Switch part, responsible for Ethernet switch. At present, the main component chip solution includes the following aspects: network processor, ADSL decoder, wireless part, Ethernet part, etc. The main functions of AP routers with ADSL interfaces are as follows. dmtG.922.1), G. liteG.922.2) and other standards; ATM functions, can implement multi-protocol encapsulation, such as RFC1483/2684 bridging, RFC1577IPOA, RFC2364PPPOA, RFC2516PPPOE built-in dialing and Other encapsulation methods; wireless codec, conforms to the series standards, currently, it mainly supports 802.11b. In the future, it supports the IEEE802.11g standard and WEP encryption. Ethernet switches enable Ethernet Switching and simultaneous access of multiple PCs; IP routing and switching functions, provides Ethernet Switching, IP routing, NAT address translation, DMZ, DHCP address allocation, MAC filtering, and IP address filtering. Management Functions Support WEB management and SNMP Simple Network Management Protocols.

In family access, you can fully consider using the AP router with ADSL interface as the home gateway, so that multiple PCs in the home can access the Internet at the same time. In actual business development, we can bind and sell "tianyitong" and other wireless services with ADSL to accelerate the development of wireless WLAN services. In actual configuration, there are two methods.

Single PPPOE session. Multiple PCs in the user's home are connected through a wired or wireless network card). The IP address, gateway, DNS, and other parameters are dynamically obtained through DHCP. The AP router is configured as a built-in PP? POE dial-up access allows you to access the Internet through the NAT address translation function provided by the AP router. In this case, the user's IP address is a private IP address. For some special applications, such as bidirectional video applications, there may be some problems after NAT translation, generally, you can configure port ing or DMZ.

Multiple PPPOE sessions. The AP router is directly configured as a bridge. Multiple users can obtain the IP address through PCPPPOE dialing. Each user can obtain a public IP address. This method does not require NAT translation, so there is no NAT penetration problem for various network application software, and maintenance is relatively simple for telecom operators, the disadvantage is that the user needs to occupy multiple IP addresses, and the demand for IP addresses will increase, and the requirements for BRAS Broadband Access Server) and RADIUS Authentication and billing systems are also relatively high.

For public hotspot Hotpot), you can fully consider using ADSL as a remote access method. Compared with traditional leased line access and optical fiber access, it can greatly save construction costs and accelerate the deployment of WLAN hotspots.

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