Transcript Slide 1

Bluetooth:
It’s not a
disease,
but it sure feels like it.
Paul J. Kreimer, M.A., CCC-A
Ariz Slali, Au.D.
Bluetooth
• What we hope to accomplish today is to:
– Answer the question of what Bluetooth is
– How Bluetooth works
– What is a Bluetooth profile and why you should
care
– Limitations and considerations
History of Bluetooth
• In 1996, a group of technology companies came together
to develop a unified standard for cell phones and computers
to communicate.
• The original technology was invented in 1994 by engineers
working at Ericsson.
• When Bluetooth was officially introduced in 1998, its
intended basic purpose was to be a wire replacement
technology in order to rapidly transfer voice and data.
• It was named after a 10th century Danish king, Harald
Blatand, or Harold Bluetooth in English. He was famous for
uniting warring factions of Sweden, Norway and Denmark.
• The technology was almost called “Flirt”. The tag line was to
be “Getting close without touching”
What is Bluetooth?
• Bluetooth is a short-range wireless setup used to
create personal networks
• To help reduce potential interference, it uses a
frequency hopping spread spectrum signal
• It uses an unlicensed radio frequency bandwidth
of 2.4 – 2.485GHz
• However, many devices currently operate in the
2.4GHz range so interference can occur
• Is omni-directional and is able to penetrate solid
objects
What is Bluetooth?
• Low power consumption was a design
consideration from the beginning
• There are three classifications, mobile
phones are typically Class 2.
– Class 1
• 100mW maximum power consumption
• 300 foot range
– Class 2
• 2.5 mW maximum power consumption
• 30 foot range
– Class 3
• 1 mW maximum power consumption
• 3 foot range
What is Bluetooth?
• Bluetooth is used for a variety of applications, such
as:
– Wireless control and communication between a mobile
phone and a wireless headset
– Wireless communication between computers and input
devices, such as keyboards, printers and mice
– Wireless replacement of serial port applications, such as
GPS receivers and medical devices (i.e. – HiPro boxes)
– Wireless networking of computers, where small amounts
of information exchange occur
– Wireless transfer of contact information and calendar
details
What is Bluetooth?
• There have been many versions of the
standard and it is constantly evolving
–
–
–
–
Version 1.0 - bad
Version 1.1 - better
Version 1.2 - usable (original RAZR used this)
Version 2.0 + EDR - passed in 2004 and
finally allowed good headsets
– Version 2.1 + EDR
– Version 3.0 + HS & Low Energy - passed
April 21, 2009
Bluetooth: Where It
Gets Confusing
• Think of profiles as capabilities or features
• Both devices have to support the same
profile for a feature to work
• There are many different profiles available
Bluetooth: Where It
Gets Confusing
• The variety of profiles includes:
– Advanced Audio Distribution Profile (A2DP), Audio /
Video Control Transport Protocol (AVRCP), Basic
Imaging Profile (BIP), Basic Printing Profile (BPP),
Common ISDN Access Profile (CIP), Cordless
Telephony Profile (CTP), Dial-Up Network Profile
(DUN), Fax Profile (FAX), File Transfer Profile (FTP),
General Audio/Video Distribution Profile (GAVDP),
Generic Object Profile (GOEP) Hands-Free Profile
(HFP), Hard Copy Cable Replacement Profile (HCRP),
Headset Profile (HSP), Human Interface Device Profile
(HID), Intercom Profile (ICP), Object Push Profile
(OPP), Personal Area Networking Profile (PAN),
Service Discovery Application Profile (SDAP), Service
Port Profile (SPP), Synchronization Profile (SYNC),
Video Distribution Profile (VDP)
Bluetooth: Profile
Soup
• Profiles important to you include:
– Headset Profile (HSP)
– Hands-Free Profile (HFP)
– Advanced Audio Distribution Profile
(A2DP)
Bluetooth: Profile
Soup
Headset Profile (HSP)
– This is the most commonly used profile and
allows mobile phones to communicate with
wireless headsets
– It only allows to ability to ring, adjust the
volume, answer a call and hang up
Bluetooth: Profile
Soup
Hands-Free Profile (HFP)
– This is commonly used to allow communication
with a car hands free system
– The extra features that HFP allows are last
number redial, call waiting and voice dialing
– Most Bluetooth headsets support both HSP and
HFP profiles. This is why the iCom conflicts
with car bluetooth systems
Bluetooth: Profile
Soup
Advanced Audio Distribution Profile (A2DP)
– This profile is used to define how high quality
mono and stereo audio information is streamed
from one device to another
– Examples include:
• Music from a mobile phone to a car audio system or a wireless
headset
• Audio from a television or stereo to a wireless headset
Grouping & Pairing &
Connecting. Oh My!
• There are three terms that are frequently interchanged,
however, need to be clearly defined.
• Grouping occurs in the Phonak software. It is when an
iCom is attached to hearing instruments to create a
hearing system.
• Pairing is when a trusted relationship is established
between two Bluetooth devices. The devices place each
other on their “buddy list”
• Connecting is when two previously paired devices
recognize each other and start talking.
Bluetooth: Pairing
• Pairing occurs when two devices agree that it is safe to
communicate with one another and create a connection
• To pair two compatible devices, a shared passkey
(password) is needed
• Many devices use the standard 0000, especially those
without keyboards for manual number input
• Once two devices are paired, they need not be re-paired
unless either device is reset or the pairing has been deleted
Bluetooth: Pairing
• The pairing process is:
1. Device A searches for other Bluetooth devices
2. Device B is found by Device A
3. Device A asks for a passkey (any user generated code)
and sends it to Device B
4. Device B sends the passkey back to Device A and
creates a trusted pairing if both passkeys are the
same
• Since the iCom doesn’t have a keyboard, the
generic code of 0000 is used
Why doesn’t this $%^**&^
thing sometimes not work?
• Make sure that the corresponding Bluetooth
profile is supported by both devices.
• Make sure the devices have Bluetooth
functionality turned on.
• Make sure that the devices you want to
communicate are paired with each other.
Why doesn’t this $%^**&^
thing sometimes not work?
• Make sure profiles match
– For devices to work together, it is important that each
device share the same profile
• One of the most common causes for devices not
to work together is when two devices do not
support the same profile. Support in both devices
is a requirement.
• Another issue is that the iCom may already be
currently connected to another device using the
same profile that is needed to connect to the new
device.
Other Considerations
• Bluetooth is a one-to-one connection. Two
receiving devices cannot be connected to two
devices at the same time.
• For example, a husband and wife, each with their
own iCom, would each need their own television
transmitter.
• Don’t forget, an intermittent Bluetooth signal
could actually be a bad cell phone signal.
Case Study #1
• I was at an office where the patient described his
hearing aid as being too soft and not being able
to hear very well at times. He would also hear a
beeping at times.
• He was a previous hearing aid user with a
profound hearing loss and wearing Naida V Ups in
both ears.
• He also said that his iCom would only last about
4 hours from a full charge, even when he didn’t
receive a call all day. He only had it paired to a
Samsung cellphone.
Case Study #1
• After talking with him for a long time and
updating the firmware in the hearing aids and
iCom, I realized the Bluetooth light on his iCom
was a solid blue and not flashing. This meant
that a signal was being streamed to the iCom,
however, there was not active call coming in.
• I reset his iCom since it was not paired with
anything else and then deleted the iCom pairing
from his phone.
Case Study #1
• I then repaired the phone. The screen that
appeared showed:
• Handsfree Headset
• Stereo Headset
• I unchecked the setting for stereo headset and
the light on the iCom was blinking.
Case Study #1
• What was happening is that the phone was using
the A2DP profile to set up a stereo headset
conenction and the phone was constantly
streaming to his iCom, thereby draining his
battery.
• This is also why he could not hear well because
the hearing aids were always in EasyBluetooth
when the iCom was on since the phone was
streaming.
• He was not even using SoundFlow most of the
time which is why he could not hear well
Case Study #2
• A patient complained that his iCom cut in and out
frequently and randomly without any rhyme or
reason.
• He could hear his hearing aids go into the
easyBluetooth program and then return to
SoundFlow for no apparent reason.
Case Study #2
• After looking at the phone, it was discovered that every
time the phone created an audible alert signal, the iCom
was trying to transmit the signal to the hearing aids.
Because the alert signal was so short, the connection didn’t
finish before the alert signal ended so the end user never
heard it.
• The patient and Audiologist assumed it was a problem with
the devices and didn’t realize that it was just how Bluetooth
works.
• For example, on my iPhone 3Gs, a signal is sent to the
iCom using A2DP every time I receive an e-mail, text
message, alarm signal, and every keyboard click. The only
way to prevent this is to turn those sounds off.
Case Study #3
• A patient was upset because he said that the
iCom was picking up interference from his wife’s
phone and was not staying paired to his.
• He said that sometimes the iCom worked with his
phone perfectly sometimes it wouldn’t.
Case Study #3
• After a lot of investigating, it turns out that he
had paired his iCom not only to his own phone,
but also to his wife’s phone, his daughter’s phone
and just about anything else with the house with
the word Bluetooth on it.
• He said that he was trying it out when he first
received it.
Case Study #3
• What was happening is that when he would wake
up in the morning, his wife’s phone was already
on. He then turned his iCom on and it would
then connect to her phone. Then he was turning
his own phone on. Then they would travel to the
store together and the iCom would pick up her
calls when they driving. Once in the store, they
would separate and then the iCom would connect
with his phone and work correctly.
• The solution: delete the other pairings.
• Take home message, “Keep your pairings to
yourself”
iCom Function
• Points to remember
– A slow steady flashing blue light on the iCom means that
the iCom is currently connected to a device that it has
been previously paired with
– A steady blue light means that the iCom is currently
receiving a streamed signal such as output from a
television streamer or during an active phone call
References
• The Official Bluetooth Technology Info Site
– www.bluetooth.com
• Wikipedia – Bluetooth Reference
– http://en.wikipedia.org/wiki/Bluetooth
• Blue Tomorrow
– http://www.bluetomorrow.com/
• Bluetooth Gagdet Guide
– http://gadget.bluetooth.com
• GSM Arena – Cellphone Reviews
– http://www.gsmarena.com
Questions
Any questions?