ANT (network)

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ANT
Developed by Dynastream Innovations Inc.
Industry Sports, health, home automation, industrial

ANT is a proprietary open access multicast wireless sensor network technology designed and marketed by ANT Wireless. It features a wireless communications protocol stack that enables semiconductor radios operating in the 2.4 GHz industrial, scientific, and medical allocation of the RF spectrum ("ISM band") to communicate by establishing standard rules for co-existence, data representation, signalling, authentication, and error detection.[citation needed]

ANT Wireless is a division of Dynastream Innovations Inc. (a Cochrane, Canada-based company), which became a subsidiary of GPS equipment manufacturer Garmin in 2006.[citation needed]

The ANT protocol is available on low-power RF transceiver chips from manufacturers such as Nordic Semiconductor (since 2005)[1] and Texas Instruments (since 2010),[2][citation needed]

Overview[edit]

ANT-powered nodes are claimed[by whom?] to be capable of acting as slaves or masters within a wireless sensor network concurrently. This means the nodes can act as transmitters, receivers, or transceivers to route traffic to other nodes. In addition, every node is capable of determining when to transmit based on the activity of its neighbors.[citation needed]

Typical applications[edit]

ANT has been primarily targeted at the sports sector, particularly fitness and cycling performance monitoring. The transceivers are embedded in equipment such as heart rate monitors, watches, cycling power meters, cadence meters, and distance and speed monitors to form wireless Personal Area Networks (PANs) monitoring a user's performance.[citation needed]

Manufacturers such as Adidas, Garmin,[3] Geonaute,[4] Nike, Suunto, Fitbit[5] and Tacx[6] have used ANT technology in their performance monitoring products.[citation needed]

Recently, ANT (company) has attempted to diversify, trying to get onto the 2.4 GHz ISM band suit range of applications in the health, home automation, and industrial sectors.[citation needed]

Technical information[edit]

ANT can be configured to spend long periods in a low-power “sleep” mode (consuming of the order of microamps of current), wake up briefly to communicate (when consumption rises to a peak of 22mA (at -5dB) during reception and 13.5mA (at -5 dB) during transmission)[7] and return to sleep mode. Average current consumption for low message rates is less than 60 microamps on some devices.[7]

Each ANT channel consists of one or more transmitting nodes and one or more receiving nodes, depending on the network topology. Any node can transmit or receive, so the channels are bi-directional.[citation needed]

ANT accommodates three types of messaging: broadcast, acknowledged, and burst. Broadcast is a one-way communication from one node to another (or many). The receiving node(s) transmit no acknowledgment, but the receiving node may still send messages back to the transmitting node. This technique is suited to sensor applications and is the most economical method of operation.[citation needed]

Acknowledged messaging confirms receipt of data packets. The transmitter is informed of success or failure, although there are no retransmissions. This technique is suited to control applications.[citation needed]

ANT can also be used for burst messaging; this is a multi-message transmission technique using the full data bandwidth and running to completion. The receiving node acknowledges receipt and informs of corrupted packets that the transmitter then re-sends. The packets are sequence numbered for traceability. This technique is suited to data block transfer where the integrity of the data is paramount.[citation needed]

Comparison with Bluetooth, Bluetooth Low Energy, and ZigBee[edit]

Versions of the Bluetooth prior to v4.0 were designed for music (the SCO and eSCO synchronous transports), rapid file transfer (ACL, asynchronous transport) between devices in a PAN such as a PDA, cell-phone, and portable computer that focused on applications with lower bandwidth requirements than that offered by WiFi. Previous and current versions of Bluetooth are not designed for large wireless sensor networks but were and still are capable of forming star networks of up to eight devices (one master and seven slaves).[8] In comparison ANT was designed for low bit rate, large scale sensor network topologies that require very low, coin cell class power consumption at every node.[citation needed]

Bluetooth 3.0 introduced the AMP (Alternative MAC/PHY) controller which means that Bluetooth can use WiFi for quick and efficient transport when both technologies are collocated in one device. This is labelled as 3.0+HS. A Bluetooth 4.0+HS device can depending on selection of transports efficiently transport data using Low Energy, Standard Bluetooth or WiFi. Apple has recently qualified devices as 4.0+HS. Similar functionality on ANT can be implemented at the application level for any devices incorporating both ANT and WiFi (or any high data rate transfer technology). As well, ANT-FS or ANT File Share is a technical specification allowing larger file transfers to be performed in an interoperable fashion at up to 60 kbit/s over the ANT protocol.[citation needed]

Bluetooth SMART is a wireless specification including radio, link layer protocols, transport protocols and ways to describe data released for low power wireless embedded devices that can operate on a single coin-cell battery from months to years, such as Wireless Sensor Network, watches, and sports equipment similar to ANT. Currently, Bluetooth SMART supports scatternets and broadcasting between devices. A mesh can be implemented on top of the scatternet. A single hop typically has communication range between 50 m to 100 m (330 ft). SMART is the hallmark feature of Bluetooth 4.0. In comparison, ANT uses adaptive isochronous transmission[9] to allow a large plurality of ANT devices to communicate concurrently without interference with one another. This allows ANT networks to scale in size to potentially tens of thousands of devices (using ANT 'shared channels',[10] 'continuous scanning mode',[11] or 'background scanning'[12]) while consuming very little to no additional resources at each node including memory or radio bandwidth.[citation needed]

Dual-mode core chip supporting Bluetooth and SMART will give SMART a quick start in the mass market of smartphones, laptops, tablets etc. This advantage of integration will also allow SMART to compete against other short range technologies, but in addition ANT has also benefited from this scale as ANT and SMART share similar RF characteristics, allowing manufacturers such as Qualcomm to include ANT as well in their connectivity devices for smartphones, tablets, etc. While SMART cannot currently compete with 6LoWPAN, ZigBee, or WirelessHART in applications requiring a large multi-hop coverage area (ANT can support mesh, but while most applications in sports are currently single hop, some devices are demonstrating usage of multi-hop such as bicycle pedal power meters, which connect pedal-to-pedal-to-cyclocomputer), SMART can compete in short-range single-hop applications.[citation needed]

SMART has debuted in devices on the market late 2011 with notable support in the iPhone with Android support coming. Microsoft has also publicly stated their support for Bluetooth SMART and their first API's are in Windows 8. Bluetooth SMART chips are already in the mass market and provided by companies such as Nordic Semiconductor, Texas Instruments, CSR, Taiyo Yuden, Epson, Quintic, Broadcom, Qualcomm, EM microelectronics, ST and many more.[citation needed] In comparison, ANT debuted onto the smartphone market in late 2010 with Sony Ericsson entering the ANT+ Alliance, and is currently supported by a unified ANT Radio Service which provides a common interface for developers to create apps across Android versions and ANT hardware such as USB sticks connected through USB OTG. Samsung has also declared their support with the launch of the Galaxy Note 3 and joined the ANT+ Alliance in 2013.[citation needed]

ANT is claimed to be anywhere from 10-50 percent more efficient than Bluetooth SMART for use in glucose monitors by executives from the Bluetooth SIG and ANT Wireless.[13][citation needed]

A more direct comparison can be drawn with ZigBee. ZigBee is based on the IEEE 802.15.4 standard PHY and Media Access Control (MAC) layers, and supports the ZigBee Alliance's own Network (NWK) and Application (APL) layers (refer to the OSI model). ZigBee's IEEE 802.15.4 PHY for the 2.4 GHz frequency band has an on-the-air data rate of 250 kbit/s,[14] compared to ANT's 1 Mbit/s,[7] requiring ZigBee to stay on air longer than ANT to transmit a given volume of data.[citation needed]

Interference immunity[edit]

ANT, ZigBee, Bluetooth, Wi-Fi, and some cordless phones all use the 2.4 GHz band (as well as 868- and 915 MHz for regional variants in the latter's case), along with proprietary forms of wireless Ethernet and wireless USB.[citation needed]

Wi-Fi/ZigBee and Bluetooth employ Direct Sequence Spread Spectrum (DSSS) and Frequency-Hopping Spread Spectrum (FHSS) schemes respectively to maintain the integrity of the wireless link.[citation needed]

ANT uses an adaptive isochronous network technology to ensure coexistence with other ANT devices. This scheme provides the ability for each transmission to occur in an interference free time slot within the defined frequency band. The radio transmits for less than 150 µs per message, allowing a single channel to be divided into hundreds of time slots. The ANT messaging period (the time between each node transmitting its data) determines how many time slots are available.[citation needed]

ANT's adaptive isochronous scheme doesn't require a master clock. Transmitters start broadcasting at regular intervals but then modify the transmission timing if interference from a neighbor is detected on a particular time slot. This flexibility allows ANT to adapt to hostile conditions but ensures there is no overhead when interference is not present.[citation needed]

If the radio environment is very crowded, ANT can use frequency agility to allow an application microcontroller-controlled "hop" to an alternative 1 MHz channel in the 2.4 GHz band which can then be subdivided into timeslots.[citation needed]

ANT+[edit]

Main article: ANT+

ANT+ is an interoperability function that can be added to the base ANT protocol. This standardization allows for the networking of nearby ANT+ devices to facilitate the open collection and interpretation of sensor data. For example, ANT+ enabled fitness monitoring devices such as heart rate monitors, pedometers, speed monitors, and weight scales can all work together to assemble and track performance metrics.[citation needed]

References[edit]

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