Bluetooth:It’s not a disease,

but it sure feels like it.

Paul J. Kreimer, M.A., CCC-AAriz 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 devices2. Device B is found by Device A3. Device A asks for a passkey (any user generated code)

and sends it to Device B4. 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.

• 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.

Why doesn’t this $%^**&^ thing sometimes not work?

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?