Evolution of LR-WPAN Standardization

Wired communications is any type movement of data between or among devices using a wired connection. Wired connections include Ethernet, fiber-optic cable for phone and other uses, cable for television and Internet systems, public switched telephone network (PSTN), CAN and MOST systems in automotive.  The stability and clarity of wired communications keeps the wire relevant in the age of wireless comms.

Advances in broadband communication and networks started more than 100 years ago. Some of the most defining moments in the history of wired network technology, which influenced the advancements it’s making today, include:

• 1876: The invention of the telephone started a revolution towards wired communications.
• 1964: With the introduction of optical fiber, the potential of wired networks skyrocketed.
• 1970: Ethernet technology, which uses a coaxial-based or twisted copper transport system, was developed.
• 1980: During this decade, researchers built the foundation for a digital subscriber line (DSL).
• 2000: Broadband technology became available to consumers. Today, more than 20 million users trust it.

In the following paragraphs, we take quick review of the evolution of the wired and wireless standardization starting from the wired telephony to wireless communication over large and small area and finally to very low power personalized wireless networks.

1. Large Coverage Area

From Wired Telephony to Cellular Telephony

The mid 20^th century witnessed a transformation from the wired telephony network to the cellular network that became pervasive and was aimed at facilitating voice communications throughout a metropolitan area. Examples of cellular standards are GSM, IS-136, IS-95.

Features of transformation to Cellular Telephony  was :

1. 1. 1. The need for mobility
      2. The cost of laying new wires increased

• • • The motivation for a personal connection independent of location to that network also increased.

1. 1. 1. Large Coverage area is provided through (1-2km) cells that cooperate with their neighbors to create a seemingly seamless network.

2. Smaller Coverage Area

Mid 80s felt the need for even smaller coverage area needed for higher user densities and the emergent data traffic. It led to the formation of the IEEE 802.11 working group for WLANs to create a wireless local area network standard.

Features of IEEE 802.11 was concerned with following features :

1. 1. 1. Ethernet matching speed
      2. Long Range( 100m)

• • • Complexity to handle seamless roaming,

1. 1. 1. Message forwarding
      2. Data throughput of 2-11Mbps

   3. Very Small Coverage Area(around a person or object):

This transformation was called as wireless personalized area network (WPANs), it was focused on a space around a person or object that typically extends up to 10m in all directions. With this in mind the IEEE 802.15 working group was formed to create WPAN standard

Features of the focus of WPANs :

1. 1. 1. Low-cost
      2. Low power
      3. Short range and very small size

Classification of WPAN

The IEEE 802.15 working group currently defined three classes of WPANs these are High Data rate WPAN IEEE 802.15.3, Medium rate WPANs (IEEE 802.15.1/Blueetooth), and Low rate WPANs(IEEE 802.15.4/LR-WPAN). These classes are differentiated by:

1. 1. Data rate : It is further classified as High data rate WPAN, Medium data rate WPAN and Low data rate WPAN
   2. Battery drain :
   3. Quality of service(QoS).

Classification based on data rate –

Based on the above three classification IEEE 802.15 find the following applications.

High Data rate WPAN IEEE 802.15.3 – For applications the requires high data rate such as Multi-media applications that require very high QoS.

Medium rate WPANs (IEEE 802.15.1/Blueetooth) – Used for applications used to handle a variety of tasks ranging from cell phones to PDA communications and have QoS suitable for voice communications.

Low rate WPANs(IEEE 802.15.4/LR-WPAN) – This is intended to serve a set of industrial, residential and medical (IRM) applications with very low power consumption and cost and quality of service(QoS) requirement not considered by the 802.15.3 and 802.15.1 WPANs.

Advantages of IEEE 802.15.4:

IEEE 802.15.4 has the following advantages:

• cheap cost
• long battery life,
• Quick installation
• simple
• extensible protocol stack

Disadvantages of IEEE 802.15.4:

IEEE 802.15.4’s drawbacks include:

• IEEE 802.15.4 causes interference and multipath fading.
• doesn’t employ a frequency-hopping approach.
• unbounded latency
• interference susceptibility

Applications of IEEE 802.15.4:

IEEE 802.15.4 Applications:

• Wireless sensor networks in the industry
• Building and home automation
• Remote controllers and interacting toys
• Automotive networks

Summary:

In this article we discussed the evolution of the low power WPAN. The main featurs of IEEE802.15.4 is:

In the next lecture we will focus on the IEEE802.15.4.