Wireless personal area network

from Wikipedia, the free encyclopedia

The Wireless Personal Area Network ( WPAN ) is a special case of the Personal Area Network . It describes short-range radio technology, the aim of which is to avoid short, typical on-the-fly cable connections.

In contrast to WLANs , WPANs bridge shorter distances - distances between 0.2 m and 50 m are typical  . This means that only the immediate environment of the sender is reached, the “personal area”.

properties

By restricting the space to a smaller space, interference from third party transmitters is less likely, and the lower transmission power also results in energy savings and thus a longer battery life, for example with notebooks.

The data transfer rates are typically lower than with WLAN . The less common VFIR-IrDA specifies a maximum data transmission rate of 16 Mbit / s, the more common FIR-IrDA offers 4 Mbit / s and Bluetooth has up to 3 Mbit / s. With WLAN, on the other hand, up to 54 Mbit / s is achieved according to the IEEE 802.11g standard.

In contrast to WLAN, WPANs typically only implement point-to-point , possibly point-to-multipoint connections. The multipoint-to-multipoint option is not provided for in the standards.

WPANs are used for ad-hoc networking of PDAs, consoles, printers, notebooks, netbooks and cell phones. Typical applications are the exchange of business cards according to the vCard standard and calendar entries for appointments. If information security is inadequate, there is a risk of snarfing .

If networks are to be set up according to the ISO-OSI model , a suitable protocol stack , for example SLIP or PPP , is often implemented via an emulated serial interface . WLANs, on the other hand, use the structure defined in IEEE 802 and only implement the lowest two layers in the model differently.

Bluetooth also offers an audio mode, which can be used to control hands-free devices and headsets . With IrDA there is the IrDA CONTROL standard, which is used for remote controls, for example.

In theory, wireless mice and keyboards can also be connected via Bluetooth or IrDA, but proprietary protocols are more common.

IEEE

The IEEE consortium divides WPANs into the following standards:

IEEE 802.15.1

IEEE 802.15.1 corresponds to the international standards of the Bluetooth SIG ( Bluetooth Special Interest Group ) from V1.2. Current standard of Bluetooth SIG has two different version 4.0 dated 17 December 2009. It contains the protocol stack (protocol stacks), with varying time required a unilateral transfer or bidirectional connection-oriented build communication.

IEEE 802.15.2

The IEEE 802.15.2 section recommends how Wireless Personal Area Networks (802.15) should work together with Wireless Local Area Networks ( 802.11 ). This includes Bluetooth®, ZigBee® , CSS and UWB.

IEEE 802.15.3

IEEE 802.15.3 is responsible for transfer rates for WPANs of 20 Mbit / s or higher. It is also the goal to achieve lower energy consumption. The area is still a suggestion (as of September 2005).

The following transmission rates are currently being discussed: 11 Mbit / s, 22 Mbit / s, 33 Mbit / s, 44 Mbit / s and 55 Mbit / s. The specification includes the Medium Access Control (MAC) and the Physical Layer (PHY) .

IEEE 802.15.4

The IEEE 802.15.4 standard deals with the transmission methods for low transmission rates. These are used, for example, for remote controls, sensors and for simple transmission networks, in particular ad-hoc networks . There are a number of variants, such as IEEE 802.15.4a CSS. For example, the ZigBee specification, which aims to ensure interoperability between devices from different manufacturers, is based on the IEEE 802.15.4 definition framework, which defines the lower layers of network access.

IEEE 802.15.5

This standard specifies how so-called mesh networks (see meshed network ) can be implemented in WPANs . This standard was published in 2009.

IEEE 802.15.6

802.15.6 is a draft for so-called Body Area Network . Devices with which little energy is available are specifically taken into account. The devices are used on, in and around a body (human or animal).

IEEE 802.15.7

Specifies the structure of PHY and MAC for the use of light as a transmission medium (see Visible Light Communications ).

literature

Individual evidence

  1. ↑ IEEE 802.15 WPAN ™ Task Group 6 (TG6) Body Area Networks . IEEE Standards Association. June 9, 2011. Retrieved March 3, 2015.
  2. ↑ IEEE 802.15 WPAN ™ Task Group 7 (TG7) Visible Light Communication . IEEE Standards Association. April 9, 2011. Retrieved March 3, 2015.