DirectBand was a North American wireless datacast network owned and operated by Microsoft. It used FM radio broadcasts in over 100 cities to constantly transmit data to a variety of devices, including portable GPS devices, wristwatches and home weather stations.
Datacasting is the broadcasting of data over a wide area via radio waves. It most often refers to supplemental information sent by television stations along with digital terrestrial television, but may also be applied to digital signals on analog TV or radio. It generally does not apply to data which is inherent to the medium, such as PSIP data which defines virtual channels for DTT or direct broadcast satellite systems; or to things like cable modem or satellite modem, which use a completely separate channel for data.
Microsoft Corporation (MS) is an American multinational technology company with headquarters in Redmond, Washington. It develops, manufactures, licenses, supports and sells computer software, consumer electronics, personal computers, and related services. Its best known software products are the Microsoft Windows line of operating systems, the Microsoft Office suite, and the Internet Explorer and Edge web browsers. Its flagship hardware products are the Xbox video game consoles and the Microsoft Surface lineup of touchscreen personal computers. As of 2016, it is the world's largest software maker by revenue, and one of the world's most valuable companies. The word "Microsoft" is a portmanteau of "microcomputer" and "software". Microsoft is ranked No. 30 in the 2018 Fortune 500 rankings of the largest United States corporations by total revenue.
DirectBand used the 67.65 kHz subcarrier leased by Microsoft from commercial radio broadcasters. This subcarrier delivers about 12 kbit/s (net after ECC) of data per tower, for over 100 MB per day per city. Data included traffic, sports, weather, stocks, news, movie times, calendar appointments, and local time.
A subcarrier is a sideband of a radio frequency carrier wave, which is modulated to send additional information. Examples include the provision of colour in a black and white television system or the provision of stereo in a monophonic radio broadcast. There is no physical difference between a carrier and a subcarrier; the "sub" implies that it has been derived from a carrier, which has been amplitude modulated by a steady signal and has a constant frequency relation to it.
DirectBand did not use the RDS (Radio Data System) subcarrier. RDS is a different system and has much lower data rate (~730 bit/s after ECC, including framing). Its much narrower subcarrier is primarily used for radio station information and traffic. DirectBand and RDS can co-exist on the same FM station.
Radio Data System (RDS) is a communications protocol standard for embedding small amounts of digital information in conventional FM radio broadcasts. RDS standardizes several types of information transmitted, including time, station identification and program information.
Since many DirectBand uses were mobile, and there was no opportunity to request retransmission of a broadcast signal, DirectBand utilized an advanced error-correction strategy that allowed for reconstruction of messages even when sizable portions of the message were lost due to buildings, tunnels or other obstructions of the FM signal. Error correction was 1/2 rate interleaved trellis with time diversity, soft-decision decode. The DirectBand data rate was in excess of 12 kbit/s after ECC.
In telecommunication, trellis modulation is a modulation scheme that transmits information with high efficiency over band-limited channels such as telephone lines. Gottfried Ungerboeck invented trellis modulation while working for IBM in the 1970s, and first described it in a conference paper in 1976. It went largely unnoticed, however, until he published a new, detailed exposition in 1982 that achieved sudden and widespread recognition.
DirectBand was a push network – new content was delivered every two minutes. Users pre-selected the virtual channels that they were interested in.
There were a variety of DirectBand receivers. All used a small (2.794 mm × 2.794 mm × 860 µm) radio receiver. Some designs added an ARM7-based processor.
ARM7 is a group of older 32-bit RISC ARM processor cores licensed by ARM Holdings for microcontroller use. The ARM7 core family consists of ARM700, ARM710, ARM7DI, ARM710a, ARM720T, ARM740T, ARM710T, ARM7TDMI, ARM7TDMI-S, ARM7EJ-S. The ARM7TDMI and ARM7TDMI-S were the most popular cores of the family. Since ARM7 cores were released from 1993 to 2001, they are no longer recommended for new IC designs; instead ARM Cortex-M or ARM Cortex-R cores are preferred.
The initial DirectBand products were a series of data watches. These had mild success, but never met expectations and production of new watches was discontinued in 2008. Recently, several other applications have surfaced, the most visible being the traffic data/local info market, particularly to auto GPS sets for Garmin and Avis. This competes directly with older RDS-based services, which operate at a substantially lower data rate.
DirectBand is a product of the Smart Personal Objects Technology (SPOT) team at Microsoft. System hardware was designed for Microsoft by SCA Data Systems of Santa Monica, California.MSN Direct is the consumer brand that Microsoft uses for devices that receive content from the DirectBand network.
The Smart Personal Objects Technology (SPOT) is a discontinued initiative by Microsoft to create intelligent and personal home appliances, consumer electronics, and other objects through new hardware capabilities and software features.
MSN Direct was an FM radio-based digital service which allowed 'SPOT' portable devices to receive information from MSN services. Devices that supported MSN Direct included wristwatches, desktop clocks, in-car GPS satellite navigation units, and even small appliances such as coffee makers. Information available through paid "channels" included weather, horoscopes, stocks, news, sports results and calendar notifications. The service also allowed users to receive short messages from Windows Live Messenger.
RDS uses a portion of the FM station spectrum immediately above the stereo signal, centered at 57 kHz (the stereo pilot frequency). RDS extends between about 55 and 59 kHz. DirectBand is above RDS, extending from about 59 kHz to 75 kHz.
On October 26, 2009, Microsoft announced that MSN Direct service would end on January 1, 2012.
Although this clearly indicated Microsoft's intent to cease usage of the service, it is not yet known whether the DirectBand technology will be sold to another company, such as one of the hardware licensees of MSN Direct (e.g. Garmin) – or whether the technology will be put in the public domain as an open source technology.
Digital audio broadcasting (DAB) is a digital radio standard for broadcasting digital audio radio services, used in many countries around the world, though not North America.
In-band on-channel (IBOC) is a hybrid method of transmitting digital radio and analog radio broadcast signals simultaneously on the same frequency.
Digital Radio Mondiale is a set of digital audio broadcasting technologies designed to work over the bands currently used for analogue radio broadcasting including AM broadcasting, particularly shortwave, and FM broadcasting. DRM is more spectrally efficient than AM and FM, allowing more stations, at higher quality, into a given amount of bandwidth, using various MPEG-4 audio coding formats.
Autofahrer-Rundfunk-Informationssystem was a system for indicating the presence of traffic information in FM broadcasts used by the German ARD network of FM radio stations from 1974. Developed jointly by IRT and Blaupunkt, it indicated the presence of traffic announcements through manipulation of the 57kHz subcarrier of the station's FM signal.
Traffic Message Channel (TMC) is a technology for delivering traffic and travel information to motor vehicle drivers. It is digitally coded using the ALERT C protocol into RDS Type 8A groups carried via conventional FM radio broadcasts. It can also be transmitted on Digital Audio Broadcasting or satellite radio. TMC allows silent delivery of dynamic information suitable for reproduction or display in the user's language without interrupting audio broadcast services. Both public and commercial services are operational in many countries. When data is integrated directly into a navigation system, traffic information can be used in the system's route calculation.
HD Radio is a trademarked term for Xperi's in-band on-channel (IBOC) digital radio technology used by AM and FM radio stations to transmit audio and data by using a digital signal embedded "on-frequency" immediately above and below a station's standard analog signal, providing the means to listen to the same program in either HD or as a standard broadcast. The HD format also provides the means for a single radio station to simultaneously broadcast one or more different programs in addition to the program being transmitted on the radio station's analog channel. It was originally developed by iBiquity. In September 2015 iBiquity was acquired by DTS bringing the HD Radio technology under the same banner as DTS' eponymous theater surround sound systems.. It was later acquired by Xperi in 2016.
G.722 is an ITU-T standard 7 kHz Wideband audio codec operating at 48, 56 and 64 kbit/s. It was approved by ITU-T in November 1988. Technology of the codec is based on sub-band ADPCM (SB-ADPCM).
FM broadcasting is a method of radio broadcasting using frequency modulation (FM) technology. Invented in 1933 by American engineer Edwin Armstrong, wide-band FM is used worldwide to provide high-fidelity sound over broadcast radio. FM broadcasting is capable of better sound quality than AM broadcasting, the chief competing radio broadcasting technology, so it is used for most music broadcasts. Theoretically wideband AM can offer equally good sound quality, provided the reception conditions are ideal. FM radio stations use the VHF frequencies. The term "FM band" describes the frequency band in a given country which is dedicated to FM broadcasting.
Subsidiary Communications Authorization (SCA) in the United States, and Subsidiary Communications Multiplex Operation (SCMO) in Canada, is a subcarrier on a radio station, allowing the station to broadcast additional services as part of its signal.
FMeXtra is a deprecated in-band on-channel digital radio broadcasting technology created by Digital Radio Express. Unlike iBiquity's HD Radio system, it uses any FM radio station's existing equipment and transmitter plant to transmit digital audio data on subcarriers instead of sidebands. It also requires no royalties for its use, which can run thousands of dollars per year for HD Radio because of the 3% of revenue on HD-2, HD-3 channels.
In digital audio data reduction technology, aptX is a family of proprietary audio codec compression algorithms owned by Qualcomm.
CCIR System B was the 625-line analog broadcast television system which at its peak was the system used in most countries. It is being replaced across Western Europe, part of Asia and Africa by digital broadcasting.
Satellite subcarrier audio is audio transmitted by way of satellite that utilizes a separate analog or digital signal carried on a main radio transmission on a specific satellite transponder. More technically, it is an already-modulated signal, which is then modulated into another signal of higher frequency and bandwidth. In a more general sense, satellite subcarrier audio is an early form of satellite radio not intended for the consumer market but was initially unencrypted, thus receivable to satellite hobbyists.
CCIR System I is an analog broadcast television system. It was first used in the Republic of Ireland starting in 1962 as the 625-line broadcasting standard to be used on VHF Band I and Band III, sharing Band III with 405-line System A signals radiated in the north of the country. The UK started its own 625-line television service in 1964 also using System I, but on UHF only - the UK has never used VHF for 625-line television except for some cable relay distribution systems.
Data Radio Channel (DARC) is a high-rate standard for encoding data in a subcarrier over radio station broadcasts,