WIBREE
1. The recent announcement of the Wibree standard seems to
have caught the industry unawares. The initial response of many analysts and
much of the media has been to categorise it as yet another competitor in the
2.4 GHz space. A significant number have announced that it obviously just a
“Bluetooth killer”. Nothing could be further from the truth. One of the most
important aspects of Wibree is that it envisages dual-mode chips that can
support both Bluetooth and Wibree. This symbiotic existence is key to Wibree’s
market success. There will also be single-mode Wibree chips that offer low
power operation, which will enable a wide range of devices to talk to these
dual mode chips.
2. Every wireless standard faces a problem of achieving a
critical mass of nodes if it is going to enable mass market applications. Wi-Fi
managed this on the back of laptops, Bluetooth managed it on the back of mobile
phones. So far none of the other prospective short range wireless technologies
have found a platform that will give them critical mass within the market
place. The design of Wibree is particularly cunning as it builds in a route to
mass deployment.
3. It is a strategy that means Wibree will redefine the speed
at which a new wireless technology can be rolled out into the market. If we
look back over the last fifty years, it typically took years for new
technologies to reach their first million products in the field. It took the
colour TV eight years to reach the million mark. The PC was faster, at 28
months, the Palm Pilot set a new record at 9 months. That record for consumer
products was shattered by the iPod, which took just 17 days. Wireless
technologies have had even slower gestations. From the first to the millionth
802.11 chip took a leisurely 4 years. Bluetooth did better, but was still a
slow starter taking 17 months from the first product to the millionth one,
although it proved exceptionally active since that point, taking just another 5
years to get to the billion mark. All existing records, both in consumer goods
and wireless technologies are set to be overturned when Wibree leaves the
starting blocks. Because of the fact that it will be integrated inside
Bluetooth chips, it is likely to reach that one million shipment milestone in
just one week.
4. That combination of Wibree within a Bluetooth chip is
vitally important in understanding its place and the role that it can fulfil.
Because low power, personal Wibree devices will be able to communicate with
handsets, it means that in time every mobile phone becomes a Wibree gateway to
the mobile network. So every Wibree device can communicate with the internet,
allowing information to be sent backwards and forwards. And because the data
rates are low, the cost of this data transfer will be a negligible portion of
the user’s monthly phone contract. That paradigm change will enable a wide
range of additional services that today are just too expensive for widespread
deployment.
5. Wibree didn’t just appear from out of the blue. Although the
current specification is still confidential a little digging produces a lot of
its history and provides a good guide to its content.
6. There is an irony in the fact that the origins of Wibree
were the alternative proposal for the radio and Media Access Controller (MAC)
for the 802.15.4 standard, which is now the basis of ZigBee and other short
range radio networks. Back in 2001 two industry groups put forward proposals
for the form of this radio. Nokia headed one of the groups and proposed a
development that was handset centric. A major tenet of their design was that “it
can be deployed with minor effort into devices already having Bluetooth, e.g. cellphones”
with the added requirement that a “common RF section with Bluetooth must be possible”.
Their vision was also broader that that of the competing camp in that it envisaged
a world of a trillion wireless, web connected devices. A key slide shows
millions of connected laptops, billions of mobile phones and trillions of what
could be interpreted as Wibree enabled devices.
7. In the event, the IEEE committee chose to adopt the
alternative proposal for the 802.15.4 standard. However, Nokia didn’t stop work
on their proposal. Over the intervening years it has developed and matured into
what has now been announced to the world as Wibree.
8. The name has also raised eyebrows. Like Bluetooth, it is a
new word that tells us little of the technology. It derivation shows some of
the same interest in northern European history and mythology that generated
Bluetooth. The “Wi” is the now obligatory prefix for “wireless”, with Nokia
claiming that the “bree” comes from the Old English word for a crossroad. But
people were not totally convinced – they have a suspicion that this definition
of bree is a Tolkien invention, as Old English dictionaries define bree as
“agitation”, “to frighten” or “eyebrow”. Both of which seem equally
appropriate. So we have “Wireless at the Crossroad”, “Wireless to be scared of”
or Wireless eyebrows”. Whichever takes your fancy; one thing is certain -
Wibree will certainly herald a new era of personal wireless connectivity. And
the engagement of the major Bluetooth silicon vendors will ensure that it will
quickly appear in hundreds of millions of handsets.
9. The original documents, plus information gleaned from the
Wibree web site give us a good idea of what it will be able to do. With the
engagement of the new partners there will be a wider input into the standard
before its public release in mid 2007 and some aspects will almost certainly
change to reflect current market requirements.
10. Wibree’s main application is to provide an ultra low power
radio within the 2.4GHz band. Low power is always determined in large part by
the application – the longer a device is active, and the more data it
transmits, the shorter its battery life will be. Wibree is aiming to produce a
radio that can transmit a small packet of data approximately every second for a
year using a small button cell, such as a CR2430, with a capacity of around
280mAH. If the duty cycle is reduced to one transmission every 15 to 30
seconds, then the battery life effectively becomes the leakage life of the
battery.
11. This low power drain is achieved by designing a radio and
protocol that lets the radio stay asleep for most of its life. It can wake up
quickly, when it will broadcast its requirement to transfer data on a number of
advertising channels across the spectrum. The receiving device, which is likely
to contain a larger battery as it will be on for more of the time, will acknowledge
the message and tell the first device which channel to send its data on. It will
then acknowledge receipt of this data, at which point both can go back to
sleep. The whole process will take less than three or four milliseconds.
12. Cost
is a key advantage in Wibree existing within a Bluetooth chipset. But it’s not
the only advantage of that symbiotic existence. A major concern about radio
deployment in the 2.4GHz band is the growing level of interference that is
likely to exist. That’s already resulting in a resurgence of interest in
Bluetooth for industrial applications because of its resilience to
interference. Where ultra low power is a requirement, there is still no satisfactory
solution – a situation that has persuaded groups such as ISA to look afresh at
their radio requirements for a robust industrial wireless standard. Wibree provides
the answer. Because the conversation between devices allows the responding device
to select the radio channel to use, it introduces the concept of frequency
agility, where the two radios can move to undisturbed parts of the spectrum for
their data transmissions. In most cases, this receiving device will be a mobile
phone, which is acting as a gateway. The same Bluetooth chip that contains the
Wibree radio within the phone will be constantly scanning the radio spectrum as
part of its adaptive frequency hopping requirement to see what spectrum is
free. It makes perfect sense to share this information with the Wibree radio to
give it the frequency agility that it needs to meet high reliability
applications. So living inside a Bluetooth chip becomes a doubly positive advantage
for Wibree.
13. The current description of Wibree firmly positions it as a low
range radio, suggesting that it will be limited to around 5 meter. That would
appear to be driven by a marketing requirement rather than a more considered
analysis of how it is going to be deployed. In that sense it’s probably the
same type of understatement that has haunted Bluetooth; although Bluetooth is
normally referred to as a short range technology for less than ten meters, the
reality is that it is successfully used for many applications over hundreds of meters.
14. Looking more closely at what we know about the parameters that
will determine Wibree range, the first point is that it will share the radio
and receiver of Bluetooth chips. The most recent generation of Bluetooth chips
have receive sensitivities around -85dBm and can directly output at transmit
powers of around +4dBm. With careful RF design that gives an open field range
better than 200 meters. The higher modulation index of Wibree suggests that for
the same receive and transmit values the link budget should be improved giving
an additional 20% of range. Dual Mode Wibree chips will use the same receiver
and transmitter technology within these chips, which means that there should be
no problem in expanding Wibree’s usage from devices that we wear or carry with
us to sensors anywhere within the house or factory floor. Adding a Power
Amplifier to boost the output to 100mw (+20dBm) should make it possible to
reach an open field range close to one kilometer. That’s going to require the
addition of power control, which isn’t mentioned within the published
documents. But as more designers see the potential of Wibree it is certain that
it will be demanded.
15. Wibree is adopting the principle of profiles to define its
most common application areas. In its initial release, these cover the watch,
sensors and Human Interface Devices (HID). Although this may seem a somewhat
esoteric selection, together they enable far more than a first glance would
suggest.
16. Taking the watch profile first, its main task would appear to
be transmitting information to a watch to allow it to act as a micro-display.
That may be seemed to be a very “James Bond” sort of usage, and time will tell
how attractive a user feature it really is. What’s important is to realise is
that it provides a method of transmitting information to any display. And the
most prevalent portable display is the screen of our mobile phone. So the
scenario can be turned around, with the watch profile being used to make a
handset a general purpose display for other devices. That can be anywhere. At
home, or in the wider world, such as public transport information broadcast
from a bus stop or in a railway carriage.
17. The receiving device doesn’t need to be static for this
scenario. A feature of the short time required to complete a data transfer
means this profile can be used with moving receivers. If we consider a
transmitter with a 100 metre range, a vehicle moving at 100 km/hr will be
within range of the transmitter for around 4 seconds – more than enough time to
pick up traffic information from a beacon. An increasing number of vehicles already
have a driver display that is Bluetooth enabled – it’s called their satellite navigation
system. There’s only a minimal incremental cost to Wibree enable it to receive additional
messages from roadside transmitters. It makes Wibree a very interesting proposition
to those developing ITS (Integrated Traffic System) applications.
18. Perhaps the killer application for the watch profile is to use
it for remote control of home entertainment, where the handset acts as a remote
control for the PVR or entertainment centre. That’s an application that has
been bubbling around for many years, but has never been cracked. It has always
been my belief that the wireless standard that can gain ownership of the
universal remote control will own the home automation space. The issue has been
the low cost of an infra red transceiver, which is way below that of any
current radio technology. Wibree will be the first wireless standard that
approaches the cost of infrared. It has an additional advantage in that if you
use your mobile phone, the set top box or PVR manufacturer can enable your
mobile phone at no cost to themselves, as it already contains the Wibree radio.
Because the Wibree watch profile lets another device “take over” the display of
a consenting handset, it offers a technology route for far more advanced
control and user feedback than is addressable with mass market remote controls.
So the PVR manufacturer can ship a simple, low cost remote control with their
box and enable the customer’s mobile phone to add additional functionality and
interactivity.
20. Finally HID is important because it takes account of latency.
Latency in wireless systems refers to the delay between something happening at
the sensor and the time that it is reported back to the receiving system.
Delays can happen for many reasons – both external factors such as
interference, and internal ones, such as the devices turning off to save power.
For many applications a short delay doesn’t matter, but for some it is vital that
data is transferred at carefully controlled times. Human Interface Devices such
as keyboards and mice are one such application where delays become very
apparent, and the HID profile addresses these concerns. The application extends
far outside these devices and is particularly relevant to industrial control
systems.
21. Putting these together, the three Wibree profiles of Watch,
Sensor and HID enable most of the prospective applications currently envisaged
by wireless device developers.
22. One of the most important features about Wibree is that it
will quickly become embedded into a wide range of mobile phones. That allows
the phone to act as a gateway for information, transmitting it back over the
network to an internet based monitoring service. In general the data
throughputs involved will be small, so the transmission costs will be low and
will not swamp the networks’ capacity.
23. It opens up a whole new market for monitoring consumer
applications that is largely untapped. Today the GPRS network is used for
Machine to Machine (M2M) and telematics applications, but these generally carry
a significant hardware cost, as they require an integrated GPRS modem as well
as an individual SIM and network contract. That prices them above what is
acceptable for consumer oriented applications. With Wibree, the additional cost
to the sensor will be the cost of a Wibree chip. The phone and contract are already
paid for by the consumer, so network operators and service providers have the platform
to enable a whole new generation of services.
24. The range of these is limited only by consumer demand and
developer imagination. The obvious ones are healthcare. Less obvious ones will
rapidly evolve. For example, consider emergency messages. If Wibree is fitted
into the airbag in your car, then whenever it is deployed in a accident, the
airbag could send an emergency call out through your phone. The cost of
implementing that is around a dollar for the chip, plus the cost of the monitoring
contract, which a network could offer for a minimal annual premium. Compare that
to the cost of current systems, which involve several hundred dollars of
hardware in the vehicle and a similar annual monitoring cost. It also plays to
the current legislative requirements for mobile phones to provide emergency
location information.
25. The same economics come to play in almost every scenario where
a low cost alarm or monitor will be within range of a consumer handset. More
and more government legislation around the world, such as that for food safety,
vehicle tolling and medical compliance raise the need for data to be recorded,
which in turns puts pressure on the market to deliver low cost wireless
sensors. Wibree is appearing just as these programs are moving towards
deployment.
26. There is one area which Wibree will revolutionise more than
any other, which is wireless healthcare. It’s another market that has been
waiting to start for many years, but there is a growing perception that its
time is ripe.
27. Earlier this year, in his presidential address to the IET, Sir
Robin Saxby, founder of ARM, predicted that healthcare monitoring would be the
next wireless revolution. He explained that we are currently in a mobile phone
economy driven world, but in the next decade his vision is that we will see a
major wealth creation growth drive within healthcare, where wireless devices
will drive things like telemedicine, helping a global aging population stay
fitter.
28. That reflects a widespread understanding that healthcare needs to encompass remote monitoring in order to service the aging population. Depending on the application this goes by a variety of names, including eHealth, telecare, assisted living and wireless wellbeing. It encompasses everything from personal fitness plans to disease control and dementia monitoring. And it provides the means for an increasing proportion of the population to live independent lives, rather than slipping into institutional care which governments find ever more difficult to fund.
29. What these initiatives need is a low cost, low power wireless
standard to allow the mass availability of sensors that are worn or which
surround us and which have a method of transmitting the data they measure to a
central server for analysis. Although personal monitors may only need a short
range, a large percentage of the lifestyle monitoring applications require
these sensors to be distributed around a house, placing a demand for significant
range coupled with low power.
30. Although solutions are available today, they tend to be
inconvenient, have short battery life, or require specialised gateway equipment
to relay the data back. What Wibree offers is a low cost wireless solution for
the sensor along with a ubiquitous gateway for the data transfer in the form of
the mobile phone. In one stroke it enables a mass market for personal health
sensors and also gives the mobile networks the means to provide monitoring
services, or the pipe for others to implement them.
31. Bluetooth, Wi-Fi and other short range wireless technologies
have already spawned a first generation of personal wireless devices and
embedded applications. However, neither address the dual requirements of the
myriad of devices that must operate off a small battery for a period of years
and also have a readily available portal to send their information back to the
internet. Wibree ticks both of these boxes.
32. More importantly, Wibree comes built within Bluetooth chips.
Current development in Bluetooth, with the evolution of a medical profile,
automation profiles and broadcast capability are paralleling the same
developments within Wibree. What that means to a product designer is that they
can start to design their products with Bluetooth today, knowing that there is
a low power roadmap that will transition the mass of consumer devices to Wibree
within a few years. That allows early deployments, which will start the collection
of data for the expert systems that will need to sit behind so many of the wireless
health applications that we will need in the future.
33. In parallel, the work currently being performed within the
Bluetooth and IEEE organisations to standardise profiles and data formats for
medical devices is also likely to encompass Wibree based products, providing
the foundations for the growth of the new wireless healthcare sector that Sir
Robin Saxby has predicted.
34. Taking all of these factors together, Wibree has the potential
to transform consumer devices. It will solve the technology and monitoring
issues that are currently hindering the adoption of wireless healthcare
services and enable a whole new generation of lifestyle, monitoring and safety
products. By making the mobile handset the gateway, it brings the network
operators into the equation. And they have the resources to aggregate and enable
service provision.
35. Today Wibree is a Nokia solution. However, it is being
supported by the major Bluetooth chip vendors including Cambridge Silicon Radio
and Broadcom. That means it will reside within the chips in almost every brand
of handset. It is unlikely that other phone vendors will not take advantage of
its presence, not least because it offers the network operators an additional
revenue stream. Its presence will make it very difficult for any other short range,
low power wireless technology to gain traction in the handset, ensuring that
Wibree is placed to own the wireless healthcare market.
36. It may not become the accepted acronym, but Wibree will enable
C2M - “Consumer to Machine” or “Consumer to Middleware” applications at a price
point that makes them mass market. M2M is only just beginning to deliver
against its promises. Wibree may result in C2M delivering an even larger
promise in a shorter timescale.
37. By the end of 2007 EZURiO expects to be able to provide the first
modular products to allow developers to start work on Wibree designs for
wireless healthcare. In the meantime we also expect to see networks engage in
investigating the infrastructure requirements to provide the data services to
support these applications.