Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs) Submission Title: [A Perspective of the BAN MAC] Date Submitted: [11 January, 2008] Source: [Dr. Okundu Omeni] Company [Toumaz Technology Ltd] Address [115 Milton Park, Abingdon, UK] Voice:[+44 1235-438-950], FAX: [+44 1235-438-970], E-Mail:[okundu.omeni@toumaz.com] Re: [n/a] Abstract: [How do the stated technical requirements constrain the PHY & MAC?] Purpose: [Explores the various technical requirements and their impact on the PHY and MAC considerations for this standard] Notice: This document has been prepared to assist the IEEE P802.15. It is offered as a basis for discussion and is not binding on the contributing individual(s) or organization(s). The material in this document is subject to change in form and content after further study. The contributor(s) reserve(s) the right to add, amend or withdraw material contained herein. Release: The contributor acknowledges and accepts that this contribution becomes the property of IEEE and may be made publicly available by P802.15. Submission Slide 1

A Perspective of the BAN MAC Dr. Okundu C. Omeni Toumaz Technology Ltd. Submission Slide 2

Motivation Submission Slide 3

Key Application Areas Proposed Medical – vital signs monitoring Sports – heart rate, speed Entertainment – gaming, video/audio Other fancy stuff… Submission Slide 4

This presentation is biased towards medical applications We need to leverage on the characteristics of this application area to develop the most efficient solution This presentation is biased towards medical applications However some valid questions are raised Submission Slide 5

The terminal nodes are power constrained and should be as simple as possible. Making them pseudo coordinators or relays would not be the best solution If the coordinator fails in a critical application, then the terminal nodes can roam to the nearest active coordinator which could easily be added as backup to the coordinator (that always listens). For this type of application the added expense is justified. Submission Slide 6

High Level Requirement This states that data rates up to 10Mbps and down to 10kbps should be supported. (see section 2.1 of document [0037-01]) This requirement needs to also be in line with the applications and MAC topology Generally the highest data rate would determine the power consumption, so we cannot get the low power benefits of low data rate if we also need to support the highest data rates. Submission Slide 7

Higher Data Rate complicates PHY choices A 10Mbps data rate requirement would mean that a bandwidth of around 10MHz/channel is required If we use a lower bandwidth, then more complex (power hungry) modulation/demodulation schemes would be required. Submission Slide 8

Higher Data Rate Applications also complicate MAC choices Audio/video streaming applications do not fit into TDMA How can these co-exist on the same network with medical application? Why should they? If they shouldn’t, then why should they all be supported by this standard? Submission Slide 9

Higher Data Rate Applications also complicate MAC choices – contd… These are really 2 different standards (like 802.15.3c & 802.15.4e) Trying to forge them into 1 would significantly complicate both the PHY and MAC and we really don’t have a chance of meeting the key objective of this standard; which is a low complexity, ultra-low power and high reliability communication standard Submission Slide 10

A Hybrid Approach Combine both TDMA and contention based access Gives the benefits of periodic and non-periodic traffic Network planning required Sensor nodes sleep when not communicating Coordinator communicates with the sensor nodes during their assigned time slots and listens otherwise Sensor nodes with critical data can transmit outside their time slots Submission Slide 11

Network Topology BS Submission Slide 12 Cluster Y Cluster X BS to BS TS BS BS to BS Communications ROAMING RF Channel X RF Channel Y Submission Slide 12

MAC Architecture TDMA Submission Slide 13

Application Scenario 1 Very low frequency vital signs monitoring e.g. blood glucose, temperature heart rate. Terminal node sleep times in the order of minutes Small data payload Very low duty cycle Coordinator should be able to support up 256 or more sensor nodes Submission Slide 14

Application scenario 2 Streaming of vital signs monitoring data e.g. ECG, EEG, motion detection Duty cycle dependent on bit rate Number of sensor nodes also dependent on bit rate Submission Slide 15

Single Lead ECG Streaming Submission Slide 16

Increasing Power, Cost, Size Wearable Batteries: Wireless Standards Flexible Thin Zinc Air Button Lithium Coin AAA/AA Rechargeable (Li based) Voltage (V) 1.0~1.5 ~ 3.0 1.5 ~ 3.6 Peak Current (mA) < 3 < 10 > 15 > 100 > 1000 Typ Charge (mAh) 30 150 220 1000 Easily Disposable ✔ ✘ 802.15.6 standard Increasing Power, Cost, Size WiFi/802.11 UWB/802.15.3 Wibree(ULP BT)/Bluetooth/802.15.1 Zigbee/802.15.4 Existing Proprietary All current standards compromise power consumption for generality, data rate/range. Submission Slide 17 connected freedom