Wireless router


Wireless router




A wireless router is a device that performs the functions of a router but also includes the functions of a wireless access point. It is commonly used to provide access to the Internet or a computer network. It does not require a wired link, as the connection is made wirelessly, via radio waves. It can function in a wired LAN (local area network), in a wireless-only LAN (WLAN), or in a mixed wired/wireless network, depending on the manufacturer and model.

Most current wireless routers have the following characteristics:
  • One or multiple NICs supporting Fast Ethernet or Gigabit Ethernet integrated into the main SoC
  • One or multiple WNICs supporting a part of the IEEE 802.11-standard family also integrated into the main SoC or as separate chips on the Printed circuit board. It also can be a distinct card connected over a MiniPCI or MiniPCIe interface.
  • So far the PHY-Chips for the WNICs are generally distinct chips on the PCB. Dependent on the mode the WNIC supports, i.e. 1T1R, 2T2R or 3T3R, one WNIC have up to 3 PHY-Chips connected to it. Each PHY-Chip is connected to a Hirose U.FL-connector on the PCB. A so-called pigtail cable connects the Hirose U.FL either to a RF connector, in which case the antenna can be changed or directly to the antenna, in which case it is integrated into the casing. Common are single-band (i.e. only for 2.4 GHz or only for 5 GHz) and dual-band (i.e. for 2.4 and 5 GHz) antennas.
  • Often an Ethernet Switch supporting Gigabit Ethernet or Fast Ethernet, with support for IEEE 802.1Q, integrated into the main SoC (MediaTek SoCs) or as separate Chip on the PCB.
  • Some wireless routers are also include a xDSL-, DOCSIS- oder a LTE-modem in addition to the other components.
  • IEEE 802.11n compliant or ready.
  • Some dual-band wireless routers operate the 2.4 GHz and 5 GHz bands simultaneously.
  • Some high end dual-band wireless routers have data transfer rates of at most 300 Mbit/s (For 2.4 GHz band) and 450 Mbit/s (For 5 GHz band).
  • Some wireless routers have 1 or 2 USB port(s). For wireless routers having 1 USB port, it is designated for either printer or desktop/mobile external hard disk drive. For wireless routers having 2 USB ports, one is designated for the printer and the other one is designated for either desktop or mobile external hard disk drive.
  • Some wireless routers have a USB port specifically designed for connecting 3G mobile broadband modem aside from connecting the wireless router to a xDSL modem.

Operating System

The most common operating system on such embedded devices is Linux. More seldom VxWorks is being used. The devices are configured over a web user interface served by a light web server software running on the device.
Asides from the OEM firmware, for a couple of wireless routers a third party firmware called OpenWrt is available. It is an open source project with the ambition to mainline support for components found in embedded devices into the Linux kernel.