Networking Hardware Considerations for a Thin Client (Windows Embedded CE 6.0)

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01/05/2012

1/5/2010

This topic discusses considerations for networking hardware on a Windows Embedded CE powered thin client.

Wired Networking Hardware

With support for a wired network connection, a thin client can connect to a corporate LAN. A wired network interface will require a 10/100 Mbps 10BaseT/100BaseT (IEEE 802.3/802.3u) network connection. To reduce costs, you can attach an Ethernet connector or an Ethernet header.

If it is necessary, you can connect an Ethernet debug port to the Ethernet connector or Ethernet header for development and debugging. Attaching an Ethernet connector or an Ethernet header lets you save the cost of including an Ethernet debug port in every hardware platform. The following list shows the requirements for the network controller:

Auto-detection and auto-switching between the 10 Mbps and the 100 Mbps data transfer rates
Detection when the network cable is disconnected
Support for direct memory access (DMA) transfers to system memory up to the maximum bandwidth allowed by the IEEE 802.3/802.3u specification

Wireless Networking Hardware

If a thin client also supports wireless connectivity, it must support the specified protocols to interact with an 802.11-compliant network. Specifically, support for WPA2-compliant 802.11g networking is required. A premium thin client device should additionally support the IEEE 802.11a wireless standard.

A thin client requires two network adapters connected either to it or located within it, to enable it to connect to both a wireless local area network (WLAN) and a wired local area network (LAN) at the same time.

Types of Wireless Networks

802.11a

IEEE 802.11a operates at a data transmission rate as high as 54 megabits per second (Mbps) and uses a radio frequency of 5.8 gigahertz (GHz). Instead of direct sequence spread spectrum (DSSS), 802.11a uses orthogonal frequency-division multiplexing (OFDM). OFDM enables data to be transmitted by sub-frequencies in parallel. This modulation mode provides better resistance to interference and improved data transmission. This higher-speed technology improves WLAN networking performance for video and conferencing applications and for future streaming video support.

802.11b

IEEE 802.11b, an enhancement to IEEE 802.11, provides standardization of the physical layer to support higher bit rates. IEEE 802.11b uses 2.45 GHz, the same frequency as IEEE 802.11, and supports two additional speeds, 5.5 Mbps and 11 Mbps. It uses the DSSS modulation scheme to provide higher data transmission rates. It can achieve the bit rate of 11 Mbps in ideal conditions. In less-than-ideal conditions, it uses the slower speeds of 5.5 Mbps, 2 Mbps, and 1 Mbps.

802.11g

IEEE 802.11g is an extension to 802.11b and supports bandwidth up to 54 Mbps. It uses the 2.4 GHz frequency for greater range. 802.11g is backward compatible with 802.11b. This means that 802.11g access points will work with 802.11b wireless network adapters and vice versa. When there is contention for bandwidth, 802.11g falls back to 802.11b to allow for 802.11b devices to operate. When an 802.11b participant is present, it significantly reduces the speed of an 802.11g network. This affects the performance of wireless data transfer.

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