board to board communication

RS232

• The large voltage swings and requirement for positive and negative supplies increases power consumption of the interface and complicates power supply design. The voltage swing requirement also limits the upper speed of a compatible interface.

RS485

RS-485 enables the configuration of inexpensive local networks and multidrop communications links. It offers data transmission speeds of 35 Mbit/sup to 10 m and 100 kbit/s at 1200 m. Since it uses a differential balanced line over twisted pair (like RS-422), it can span relatively large distances (up to 4,000 feet (1,200 m)). A rule of thumb is that the speed in bit/s multiplied by the length in meters should not exceed 108. Thus a 50 meter cable should not signal faster than 2 Mbit/s

Serial to Ethernet (RS232 to RS485) converter

USB

USB version 1.1 supported two speeds, a full speed mode of 12Mbits/s
USB 2.0, also known as hi-speed USB. This hi-speed USB is capable of supporting a transfer rate of up to 480 Mbps
USB 3.0 is the latest version of USB release. It is also called as Super-Speed USB having a data transfer rate of 600 Mbps

USB2.0 to Serial

USB2.0 hub

USB 3.0

7 port usb3.0 PCI interface

Sata

1.0  150 MB/s 

2.0  300 MB/s

3.0  600 MB/s

Wireless

WIFI

802.11b    2.4 GHz   11 Mbps

• Pros of 802.11b - lowest cost; signal range is good and not easily obstructed
• Cons of 802.11b - slowest maximum speed; home appliances may interfere on the unregulated frequency band

802.11a   5 GHz   54 Mbps

• Pros of 802.11a - fast maximum speed; regulated frequencies prevent signal interference from other devices
• Cons of 802.11a - highest cost; shorter range signal that is more easily obstructed

802.11g   2.4 Ghz   54 Mbps

• Pros of 802.11g - fast maximum speed; signal range is good and not easily obstructed
• Cons of 802.11g - costs more than 802.11b; appliances may interfere on the unregulated signal frequency

802.11n   2.4 Ghz   300 Mbps

• Pros of 802.11n - fastest maximum speed and best signal range; more resistant to signal interference from outside sources

• Cons of 802.11n - standard is not yet finalized; costs more than 802.11g; the use of multiple signals may greatly interfere with nearby 802.11b/g based networks.

802.11ac   5 GHz & 2.4 Ghz   1300 Mbps on the 5 GHz band plus up to 450 Mbps on 2.4 GHz

Bluetooth

 Bluetooth supports a very short range (approximately 10 meters) and relatively low bandwidth (1-3 Mbps in practice) designed for low-power network devices like handhelds. The low manufacturing cost of Bluetooth hardware also appeals to industry vendors.