Exploring wireless standards and means.
Over the past decade, wireless technology has revolutionized access to information. From the office to the home, wireless connectivity for most computing devices has become readily available, but the appeal of wireless extends well beyond these applications. Increasingly, users and manufacturers in physical security, healthcare, fleet management, retail, industrial automation, and other businesses seek to improve the value of their products and services by adding untethered network connectivity. Designers who want to capitalize on the growing acceptance of wireless in their product must consider factors including certification and regulatory requirements, power usage, data throughput, data security, physical size, and perhaps most critically, which wireless standards to adopt.
IEEE 802.11 is a set of standards defining wireless local area network (WLAN) data communications in the 2.4 GHz and 5 GHz frequency bands. The most popular are those defined by the 802.1lb and 802.11g standards, which provide reasonable range and bandwidth. The emerging IEEE802.11n draft standard boasts throughput up to a whopping 600 Mb/s, operates in the 5 GHz frequency band, and is also backwards compatible with 802.1la. Why is a second frequency band important? In many venues, the 2.45 GHz band is saturated. Hospitals, for example, look to segment their wireless traffic between these two bands depending on the application (computers on one, medical equipment on another).
IEEE 802.15.4 is a standard which specifies the physical layer and media access control for low-rate wireless personal area networks (WPAN). Zigbee, WirelessHART, MiWi, and 6LoWPAN are built on top of 802.15.4, providing a complete networking solution. IEEE standard 802.15.4 intends to offer the fundamental lower network layers of a type of wireless personal area network (WPAN) which focuses on very low cost, low speed (<250 kbits/s), and very low power consumption.
IEEE802.15.1 (aka Bluetooth) is another WPAN protocol which is found deployed in devices which are transient members of small networks. It is ubiquitous in cell phones and earpieces. It is also found in some HID (human interface devices) products like keyboards, mice, and gaming controllers. It typically consumes more power than 802.15.4 devices and costs more per node, but it supports higher data throughput (1 Mb/s to 3 Mb/s) and wider range. For those needing longer range communications, there are additional standards for cellular, satellite, and point-to-point data communications.
Wireless standards have driven interoperability between products from various vendors. Additional initiatives like the Wi-Fi alliance have advanced this cause. Module vendors have made wireless enablement easier to implement, and advancing wireless technology standards are driving improved range, reduced power consumption, and improved network integrity. Now is a great time to add wireless to an embedded product.
By Daryl R. Miller
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|Author:||Miller, Daryl R.|
|Publication:||ECN-Electronic Component News|
|Date:||Aug 1, 2009|
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