IEEE 802.15.3 High-Rate WPAN Overview

1. IEEE 802.15.3 High-Rate WPAN Overview Timo Vanhatupa

2. 83180 Wireless LANs / Langattomat l�hiverkot Contents IEEE 802.15.3 standardization overview History, requirements Reference model Network topology Network operation Quality of Service (QoS) Security

3. 83180 Wireless LANs / Langattomat l�hiverkot Standardization overview � History, requirements History Work started: November 1999 Standard ready: June 2003 Main applications Personal area multimedia: audio, video Wireless data transfer between consumer multimedia devices Requirements High data rate Low power consumption Low cost Fast configuration QoS support Security Ad-hoc topology The IEEE 802.15.3 standard is designed from scratch to support personal area multimedia applications such as video and audio streams, and serve as cable replacement for consumer devices. The target applications include data transfer between consumer multimedia devices, such as video streaming from digital video recorder to a display and transferring large files (audio, video, documents) between devices. These applications require large throughput with optionally real time delay requirements. The devices are usually small battery operated devices with low processing capacity. The requirements set for this standard include high data rate, low power consumption, low cost, fast configuration, QoS support, and security. These requirements should be fulfilled in ad-hoc topology.The IEEE 802.15.3 standard is designed from scratch to support personal area multimedia applications such as video and audio streams, and serve as cable replacement for consumer devices. The target applications include data transfer between consumer multimedia devices, such as video streaming from digital video recorder to a display and transferring large files (audio, video, documents) between devices. These applications require large throughput with optionally real time delay requirements. The devices are usually small battery operated devices with low processing capacity. The requirements set for this standard include high data rate, low power consumption, low cost, fast configuration, QoS support, and security. These requirements should be fulfilled in ad-hoc topology.

4. 83180 Wireless LANs / Langattomat l�hiverkot Reference model The standard defines the physical and MAC layers and does not require a usage of any specific higher layer protocol. The standard uses Frame Convergence Sublayers (FCSL) on top of the MAC layer. Only 802.2 FCSL is required. Thus, it is possible to use e.g. IP stack on top of 802.15.3 (using 802.2 FCSL). Likewise, the usage with other networking technologies is possible by implementing network layer routing function in one of the piconet devices. This device acts as a gateway between the networks. The implementation of the gateway functionality is out of the scope of the standard. Higher layer protocols other than IP are also possible. Optional FCLS include IEEE 1394 and Universal Serial Bus (USB) FCLSs. If the device implements e.g. USB FCLS, it can operate as a wireless USB. The standard defines the physical and MAC layers and does not require a usage of any specific higher layer protocol. The standard uses Frame Convergence Sublayers (FCSL) on top of the MAC layer. Only 802.2 FCSL is required. Thus, it is possible to use e.g. IP stack on top of 802.15.3 (using 802.2 FCSL). Likewise, the usage with other networking technologies is possible by implementing network layer routing function in one of the piconet devices. This device acts as a gateway between the networks. The implementation of the gateway functionality is out of the scope of the standard. Higher layer protocols other than IP are also possible. Optional FCLS include IEEE 1394 and Universal Serial Bus (USB) FCLSs. If the device implements e.g. USB FCLS, it can operate as a wireless USB.

5. 83180 Wireless LANs / Langattomat l�hiverkot Physical layer development IEEE 802.15.3 PHY Included in the standard 11, 22, 33, 44, 55 Mbit/s Unlicensed 2.4 GHz ISM band IEEE 802.15.3a PHY Physical layer specification, extensions to 802.15.3 MAC Higher data rates required in the future (over 110 Mbit/s) Ultra Wide Band (UWB) technology based Project started December 2002 Work ongoing, slow progress Requires regulatory actions, currently illegal in many countries Planned 2004, delayed Disagreements in the task group The IEEE 802.15.3a standard is an alternative higher data rate physical layer to the standard 802.15.3. Thus, it has mainly the same requirements than 802.15.3. However, an additional requirement for a higher data rate has been added because a wireless video distribution and The IEEE 802.15.3 standard defines a physical layer operating in the unlicensed 2.4 GHz ISM band (Industrial, Scientific, and Medical). It provides data rates of 11, 22, 33, 44, 55 Mbit/s High-Definition Television (HDTV) is expected to come more prevalent in the future. The usage of multiple simultaneous video streams requires data rates over 110Mbit/s, which is over the capabilities of the 802.15.3 standard. Ultra Wide Band (UWB) is planned to be used as a technology for implementing the higher data rate. The frequency range used in the standard is up to 24 GHz. The UWB technology will use wide frequency band shared by the current users. It is currently illegal in the most of the Europe until the regulatory bodies have created necessary regulations. The main concern is the amount of interference UWB systems create to existing communication systems, such as GPS and cellular networks. The interference is major issue because of the wide frequency band that is used by UWB systems. The development of the standard is progressing slowly due to disagreements in the task group. The IEEE 802.15.3a standard is an alternative higher data rate physical layer to the standard 802.15.3. Thus, it has mainly the same requirements than 802.15.3. However, an additional requirement for a higher data rate has been added because a wireless video distribution and The IEEE 802.15.3 standard defines a physical layer operating in the unlicensed 2.4 GHz ISM band (Industrial, Scientific, and Medical). It provides data rates of 11, 22, 33, 44, 55 Mbit/s High-Definition Television (HDTV) is expected to come more prevalent in the future. The usage of multiple simultaneous video streams requires data rates over 110Mbit/s, which is over the capabilities of the 802.15.3 standard. Ultra Wide Band (UWB) is planned to be used as a technology for implementing the higher data rate. The frequency range used in the standard is up to 24 GHz. The UWB technology will use wide frequency band shared by the current users. It is currently illegal in the most of the Europe until the regulatory bodies have created necessary regulations. The main concern is the amount of interference UWB systems create to existing communication systems, such as GPS and cellular networks. The interference is major issue because of the wide frequency band that is used by UWB systems. The development of the standard is progressing slowly due to disagreements in the task group.

6. 83180 Wireless LANs / Langattomat l�hiverkot Network topology Piconet (~10m range) Peer-to-peer communication between devices Piconet Coordinator (PNC) is responsible of piconet management (beacons, timeslot reservation) Possibly child piconets Maximum of 243 devices in piconet Piconet Identifier (PiconetID) is used for identifying the piconets Devices form an ad-hoc network called a piconet, where one device is required to be a Piconet Coordinator (PNC). The configuration procedure required when devices join and leave the network is designed to be simple. The standard also allows a device to form a child piconet. The data is transferred directly between the devices in Peer to Peer (P2P) fashion. The standard enables dynamic group membership for the devices, meaning that devices may flexibly join and leave the network. The size of the network is small (about 10 m).Devices form an ad-hoc network called a piconet, where one device is required to be a Piconet Coordinator (PNC). The configuration procedure required when devices join and leave the network is designed to be simple. The standard also allows a device to form a child piconet. The data is transferred directly between the devices in Peer to Peer (P2P) fashion. The standard enables dynamic group membership for the devices, meaning that devices may flexibly join and leave the network. The size of the network is small (about 10 m).

7. 83180 Wireless LANs / Langattomat l�hiverkot Different piconet types If there are no free channels, a device may create a dependent piconet If two piconets operate in the same channel, one is parent piconet and other is dependent piconet Dependent piconet Child piconet PNC belongs as a device in the parent piconet Extends the coverage area of the piconet Neighbor piconet Does not extend the coverage area Dependent piconets are Autonomous They have distinct PiconetIDs They use a dedicated time slot from the parent PNC called Channel Time Assignment (CTA) to share the time between piconets Dependent piconet can be either a child piconet or a neighbor piconet. In the child piconet, PNC belongs as a device in the parent piconet. Thus, this extends the coverage area of the piconet. Both types are autonomous, and they have distinct piconet identifiers. They use a dedicated time slot from the parent PNC called Channel Time Assignment (CTA) to share the time between piconets. Dependent piconet can be either a child piconet or a neighbor piconet. In the child piconet, PNC belongs as a device in the parent piconet. Thus, this extends the coverage area of the piconet. Both types are autonomous, and they have distinct piconet identifiers. They use a dedicated time slot from the parent PNC called Channel Time Assignment (CTA) to share the time between piconets.

8. 83180 Wireless LANs / Langattomat l�hiverkot Device responsibilities Piconet Coordinator (PNC) Periodically sends beacon frames containing necessary information for piconet operations Supplies timing with the beacon Manages QoS, power save modes, and access control Assigns time slots to each device and distributes payload protection keys All devices are not required to be able to act as PNC Enables cheap and simple implementations

9. 83180 Wireless LANs / Langattomat l�hiverkot Network operations - Piconet creation Device must make sure that there are no existing piconets using the same channel Passive scanning is used to detect existing piconets Device goes through all the channels supported by the physical layer Device listens the beacon frames from PNCs A device creating a piconet becomes PNC Selects the channel Starts to transmit beacon frames Before creating a new piconet, a device must make sure there is no other piconet in the same channel. This is done with passive scanning. Each PNC sends periodic beacon messages that can be listened. If no channels are free, a device can form a dependent piconet. Before creating a new piconet, a device must make sure there is no other piconet in the same channel. This is done with passive scanning. Each PNC sends periodic beacon messages that can be listened. If no channels are free, a device can form a dependent piconet.

10. 83180 Wireless LANs / Langattomat l�hiverkot Network operations - Joining to the piconet Piconets are discovered using passive scanning Device authenticates with PNC Device exchanges the capability information with PNC (PHY data rates supported, power management status, buffer space, capability to act as PNC etc.) Device sends association request to join the piconet PNC sends association response After joining to the piconet, the device information is broadcasted with the beacon

11. 83180 Wireless LANs / Langattomat l�hiverkot Network operations � PNC handover Changing PNC during the operation (PNC handover) When active PNC leaves the network or runs out of battery, another device may take over PNC responsibilities When new device joins the piconet If the new device is more capable and the current security policies allow it, then the PNC has the option of handing over control of the piconet to the device that has just joined PNC handover maintains all existing time allocations so that there is no interruption in the delivery of data in the piconet PNC selects the best device among those that have the PNC Capable bit set

12. 83180 Wireless LANs / Langattomat l�hiverkot Quality of Service (QoS) IEEE 802.15.3 supports various traffic types with different QoS requirements Best-effort data without reservations (contention based) PNC allocates resources (slots) for devices Devices make requests Periodic slot reservation for synchronous data Voice, video Aperiodic reservation for asynchronous data Allocates a certain time for sending packets Bursty data transmission: file transfer etc.

13. 83180 Wireless LANs / Langattomat l�hiverkot Security - 802.15.3 MAC defines two security modes Mode 0 - mandatory Device does not use any authentication or encryption methods to protect the transmitted data Access Control List (ACL) is available Mode 1 - optional Provided security services ACL Mutual authentication Key management: key establishment, key transport, verifying the authenticity of the keys Data encryption Message integrity protection (data, beacon, commands) Freshness

14. 83180 Wireless LANs / Langattomat l�hiverkot Security mode 1 Offers three security suites Elliptic curve Menezes-Qu-Vanstone (ECMQV) Koblitz-283 128-bit security NTRUEncrypt 251-1 80-bit security RSA-OAEP 1024-1 80-bit security Devices supporting security mode 1 must implement at least one security suite

15. 83180 Wireless LANs / Langattomat l�hiverkot References [1] T. Cooklev, �Wireless Communication Standards, A Study of 802.11, 802.15, and 802.16�, IEEE Press, 2004. [2] IEEE 802.15.3-2003, �IEEE Standard for Telecommunications and Information Exchange Between Systems - LAN/MAN Specific Requirements - Part 15.3: Wireless Medium Access Control (MAC) and Physical Layer (PHY) Specifications for High Rate Wireless Personal Area Networks (WPAN)�, June 2003. [3] IEEE 802.15.3 Task Group, http://www.ieee802.org/15/pub/TG3.html [4] J. Karaoguz, "High-rate wireless personal area networks," IEEE Communications Magazine, vol. 39, no. 12 , pp. 96 � 102, Dec. 2001. [5] Timo Vanhatupa, Antti Koivisto, Ari Takku, Marko H�nnik�inen and Timo D. H�m�l�inen, �Wireless Technology Evaluation for the Vuores Suburb�, Technical report, Institute of Digital and Computer Systems, Tampere University of Technology, Finland, February 2005.