2013年5月27日 星期一

Bluetooth History & BT4.0 (BLE)

BLE now has become a trend for future device which aiming to have longer battery life time and applications
(BLE~Bluetooth Low Energy), which allow device to carry smaller battery in device.
It can not only downsize the product design, but also be much closer to environmental friendly



Started from iPhone4S, now there are more and more handheld devices are carrying BLE.
(iPhone 4s, iPhone 5, New iPad, iPad mini, New iPod touch.).
For Android system, Samsung has launched SDK
http://raytaccorp.blogspot.tw/2013/05/samsung-ble-sdk-bluetooth-40.html
According to Google I/O 2013,  also confirmed they will included BLE in this year.
http://raytaccorp.blogspot.tw/2013/05/google-announces-bluetooth-smart-ready.html
Win8 and latest Win7 are also Bluetooth 4.0-compatible PC

Apparently, BLE will be the main stream For handheld device.


According to the report:
 http://ankitmathur111.wordpress.com/2012/06/20/bluetooth-2-0-3-0-and-4-0-discussed/

According to Mike Foley, executive director of the Bluetooth SIG (Special Interest Group), the key new feature of Bluetooth 4.0 is its low-energy technology. This lets device manufacturers replace proprietary sensor technology with Bluetooth, which is a more widely adopted standard. An obvious example is in the health and fitness category. Most pedometers, heart rate straps, and blood glucose monitors are designed to only talk to a specific wristwatch or control unit. If these same devices had Bluetooth 4.0, they could speak to any Bluetooth 4.0 device, be it phone or computer, without requiring an intermediary.

This version of Bluetooth is thus targeted specifically for small battery-operated devices like Nike+ sensors, Fitbits, and similar products that require almost no power. Foley envisions that gyms and fitness centers would have Bluetooth-enabled computers so that you could automatically upload your fitness stats to the cloud after you finish your workout, for example. The first such device is a Dayton heart-rate chest strap using a Bluetooth 4.0 chip from Nordic Semiconductor.


History of BT 

Bluetooth v1.0 and v1.0B

Versions 1.0 and 1.0B had many problems, and manufacturers had difficulty making their products interoperable. Versions 1.0 and 1.0B also included mandatory Bluetooth hardware device address (BD_ADDR) transmission in the Connecting process (rendering anonymity impossible at the protocol level), which was a major setback for certain services planned for use in Bluetooth environments.

Bluetooth v1.1

  • Ratified as IEEE Standard 802.15.1-2002
  • Many errors found in the 1.0B specifications were fixed.
  • Added possibility of non-encrypted channels.
  • Received Signal Strength Indicator (RSSI).

Bluetooth v1.2

This version is backward compatible with 1.1 and the major enhancements include the following:
  • Faster Connection and Discovery
  • Adaptive frequency-hopping spread spectrum (AFH), which improves resistance to radio frequency interference by avoiding the use of crowded frequencies in the hopping sequence.
  • Higher transmission speeds in practice, up to 721 kbit/s, than in v1.1.
  • Extended Synchronous Connections (eSCO), which improve voice quality of audio links by allowing retransmissions of corrupted packets, and may optionally increase audio latency to provide better concurrent data transfer.
  • Host Controller Interface (HCI) operation with three-wire UART.
  • Ratified as IEEE Standard 802.15.1-2005
  • Introduced Flow Control and Retransmission Modes for L2CAP.

Bluetooth v2.0 + EDR

This version of the Bluetooth Core Specification was released in 2004 and is backward compatible with the previous version 1.2. The main difference is the introduction of an Enhanced Data Rate (EDR) for faster data transfer. The nominal rate of EDR is about 3 Mbit/s, although the practical data transfer rate is 2.1 Mbit/s. EDR uses a combination of GFSK and Phase Shift Keyingmodulation (PSK) with two variants, π/4-DQPSK and 8DPSK. EDR can provide a lower power consumption through a reduced duty cycle.
The specification is published as “Bluetooth v2.0 + EDR” which implies that EDR is an optional feature. Aside from EDR, there are other minor improvements to the 2.0 specification, and products may claim compliance to “Bluetooth v2.0″ without supporting the higher data rate. At least one commercial device states “Bluetooth v2.0 without EDR” on its data sheet.

Bluetooth v2.1 + EDR

Bluetooth Core Specification Version 2.1 + EDR is fully backward compatible with 1.2, and was adopted by the Bluetooth SIG on July 26, 2007.
The headline feature of 2.1 is secure simple pairing (SSP): this improves the pairing experience for Bluetooth devices, while increasing the use and strength of security.
2.1 allows various other improvements, including “Extended inquiry response” (EIR), which provides more information during the inquiry procedure to allow better filtering of devices before connection; and sniff subrating, which reduces the power consumption in low-power mode.

Bluetooth v3.0 + HS

Version 3.0 + HS of the Bluetooth Core Specification was adopted by the Bluetooth SIG on April 21, 2009. Bluetooth 3.0+HS provides theoretical data transfer speeds of up to 24 Mbit/s,though not over the Bluetooth link itself. Instead, the Bluetooth link is used for negotiation and establishment, and the high data rate traffic is carried over a collocated 802.11 link.
The main new feature is AMP (Alternate MAC/PHY), the addition of 802.11 as a high speed transport. The High-Speed part of the specification is not mandatory, and hence only devices sporting the “+HS” will actually support the Bluetooth over 802.11 high-speed data transfer. A Bluetooth 3.0 device without the “+HS” suffix will not support High Speed, and needs to only support a feature introduced in Core Specification Version 3.0  or earlier Core Specification Addendum 1.

L2CAP Enhanced modes
Enhanced Retransmission Mode (ERTM) implements reliable L2CAP channel, while Streaming Mode (SM) implements unreliable channel with no retransmission or flow control. Introduced in Core Specification Addendum 1.
Alternate MAC/PHY
Enables the use of alternative MAC and PHYs for transporting Bluetooth profile data. The Bluetooth radio is still used for device discovery, initial connection and profile configuration, however when large quantities of data need to be sent, the high speed alternate MAC PHY 802.11 (typically associated with Wi-Fi) will be used to transport the data. This means that the proven low power connection models of Bluetooth are used when the system is idle, and the faster radio is used when large quantities of data need to be sent. AMP links require enhanced L2CAP modes.
Unicast Connectionless Data
Permits service data to be sent without establishing an explicit L2CAP channel. It is intended for use by applications that require low latency between user action and reconnection/transmission of data. This is only appropriate for small amounts of data.
Enhanced Power Control
Updates the power control feature to remove the open loop power control, and also to clarify ambiguities in power control introduced by the new modulation schemes added for EDR. Enhanced power control removes the ambiguities by specifying the behaviour that is expected. The feature also adds closed loop power control, meaning RSSI filtering can start as the response is received. Additionally, a “go straight to maximum power” request has been introduced. This is expected to deal with the headset link loss issue typically observed when a user puts their phone into a pocket on the opposite side to the headset.

Bluetooth 4.0 (BLE) Bluetooth low energy

This version's development
  • Ease of implementation and multi-vendor interoperability
  • Ultra-low peak, average and idle mode power consumption
  • Low cost of integration
  • Power handling
  • Resistance to interference
Bluetooth Low Energy technology extends the personal area network (PAN) to include Bluetooth enabled devices that are powered by small, coin-cell batteries. With low energy technology, sports and health care equipment, human interface (HIDs) and entertainment devices are enhanced. The technology can be built into products such as watches, wireless keyboards, gaming and sports sensors, which can then connect and communicate with host devices, such as mobile phones and personal computers.



Edied by Raytac Corporation (www.raytac.com)
BLE (BT4.0) by Nordic nRF51822 Chip


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