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Technology Area | Market Needs | State-of-the-Practice | Issues to Consider | References Technology AreaAugmentative and Alternative Communication (AAC) devices with wireless communication capabilities have been identified as a high priority technology need by augmented communicators, clinicians, researchers and manufacturers. Communications technologies (e.g. cell phones, wireless phones, the Internet) are providing new and exciting opportunities (e.g. social networking, recreation, education, work) to many individuals. In order for augmented communicators to gain full access to these opportunities, their AAC devices must have appropriate wireless capabilities. Wireless input capabilities may improve the ease of use, comfort, social acceptance and communication rate of AAC devices. [ Top of Page ] Market NeedsThe world is rapidly becoming interconnected and networked via a communications infrastructure composed of phone lines, coaxial and fiber optic cables and wireless links. Common examples of wireless technologies include AM and FM radios; cordless phones; cell phones; infrared remote controls; the Global Positioning System (GPS) and infrared data ports on personal computers (PC). There has been a recent explosion of new wireless technologies that enhance a person's ability to communicate, gain access to the Internet (and Internet resources), and allow computers to communicate with one another and to peripheral devices such as printers. Access to personal computers, the Internet and communication technology provides persons with educational and work opportunities, improved safety, social networking (e.g. email, personal web sites), daily living (e.g. online shopping) and financial transactions (e.g. banking and investing). Inability to access these resources places a person at a disadvantage that will increase as this technology becomes even more pervasive within our society. Augmented communicators would benefit from wireless input technology that eliminates tethering to the AAC device and allows them to switch quickly and effortlessly from one input device to another (i.e. to relieve fatigue, personal preference or in response to changing circumstances). Clinicians would benefit by being able to quickly set up and evaluate communication performance with different input technologies (e.g. infrared head pointers, eye gaze) without having to install special software or modify AAC device parameters. Personal computers with wireless input capabilities may eliminate the need to customize computers - all such computers would be equally accessible to all workers regardless of their abilities. All workers would use the same computers, in the same manner, in the same locations. AAC devices are needed that improve the user's ability to communicate one-on-one and in groups. Users now achieve limited privacy by having their communication partner read their text display or by reducing the volume of their speech synthesizer. Reading the output display impedes eye contact and other non-verbal cues, and is inappropriate when the communication partner has poor eyesight, when display glare is present or when a number of persons participate in the conversation. Reducing the output volume is a poor solution in noisy environments or when the communication partner has poor hearing or for phone conversations. However, persons who are not part of the conversation may invade the user's privacy accidentally or by eavesdropping. Privacy may be a special concern when medical or financial matters are being discussed. Wireless technology should provide the improved capability for private communication between two AAC users, between an AAC user and a group of AAC users or between the AAC user and someone utilizing a cell phone or hand held computer (e.g. a Palm PilotT). Augmented communicators have a critical need to have full access to voice communication technology such as cordless phones, cell phones, and pagers. More than three-quarters of respondents to a recent survey by the United Cerebral Palsy Association expressed a desire to use the Internet. Despite difficulties accessing and using telephones, they are still the preferred method of communication because they are readily available (other means of communication are perceived to be less available). [1] An environmental control unit (ECU) is a piece of equipment that allows a person to control aspects of their environment (e.g. temperature, humidity, lighting, window blinds) and provide access to electronic media technology (e.g. radio, CD player, television). ECUs assist some persons with functional limitations to independently control their daily living space and can increase their ability to participate in school, work and leisure activities. The increased independence that comes with an ECU can reduce the need for a paid attendant, cut down on the demands put on family members and friends, and give the augmented communicator a greater sense of privacy and independence. [ Top of Page ] State-of-the-PracticeAAC devices currently offer a range of capabilities for accessing the telephone, Internet and controlling the local environment. These capabilities include:
AAC devices
have recently become available with both Ethernet ports and wireless
capabilities that "lets you get online in three different
ways: through its built-in 56 K modem or 10/100BASE-T Ethernet port
or - if you're on the move - wirelessly with the Airport feature."
The user can maintain their wireless link while "roaming" anywhere
within 100 feet of the AirPort base station. [2] AAC devices are sometimes used to control other devices such as a television or environmental control unit (ECU) via its programmable infrared port. An ECU has four basic sections: the control interface (the user's method of access), a processor (interprets user input and prepares the information to be transmitted), a transmitter (generates the wireless communication signal) and the receiver (receives and responds to the wireless signal). ECUs utilize a variety of wireless communication media including: ultrasound, infrared (IR), and radio frequency (RF) transmissions. Some devices controlled by ECU have built-in receivers (e.g. televisions, garage door openers). Other devices (e.g. lights) may require a separate receiver - generally supporting only a simple ON/OFF functionality. [4] Phone lines, digital service lines, cell phones, cordless phones, pagers, modems, local area networks (LAN), and the Internet are all part of our communications infrastructure. Infrared and "spread spectrum" are two important wireless communication technologies. The IrDA (InfraRed Data Association) has established a wireless standard that supports short-range (generally 1 meter or less, greater distances are sometimes supported with more powerful IR transmitters), bi-directional communication and high-speed data transfer using infrared light. Briefly, each color perceived by the human eye corresponds to a different frequency ("cycles per second" - like the vibrations per second of a piano string). Blues and violets have the highest frequencies among visible colors. Oranges and reds have the lowest frequencies among visible colors. Infrared (frequencies immediately below red) light is not visible but can be felt - being perceived as heat. IRda is a "line-of-sight" communication technology. IRda ports must also be properly aligned (generally, the orientation of the infrared port axis' must be within 15 degrees of each other) in order to function properly. Personal computers, personal digital assistants, Palm devices, printers, fax machines, cell phones, pagers and digital cameras are among the electronic devices with IRda capabilities. [5] Spread spectrum communication differs from so-called narrow band communication (such as that used by AM or FM radios) by encoding information across many frequencies. Briefly, AM ("amplitude modulated") radio communication encodes information (music for instance) by increasing or decreasing the amplitude (analogous to height) of a carrier wave (analogous to plucking a string hard or soft). The AM carrier frequency remains constant but its amplitude changes over time. Another strong radio signal at the carrier frequency can interfere with or block the AM signal. In contrast, for spread spectrum communication, noise at any given frequency will only interfere with a small portion of the total signal and have little overall effect. Spread spectrum can support many communication channels in the same environment without having these channels interfere with one another. In addition, spread spectrum communication has very little power at any one frequency and therefore does not significantly interfere with narrow band communication signals. Spread spectrum communication is utilized for cell phones (wide area networks), local area networks (LAN) and personal area networks (PAN). Different communication standards (utilizing variants of spread spectrum communication) have been established for each of these applications. Cell phones are part of wide area networks primarily supporting voice communication. As a person roams about, the communication link to their cell phone is transparently handed off from one base station (or group of base stations) to another. From the perspective of the cell phone user, it appears that they have a single, unbroken communication link. Cell phones that are able to access and utilize Internet resources have recently become available in the marketplace [6]. It is expected that in the future, cell phones adhering to the so-called 3G (3rd Generation) wireless cell phone standard will provide high quality voice communication and full Internet access (e.g. email, streaming audio and video, web browsing, file transfers etc). [7] HomeRF wireless technology is focused on the market for home-based local area networks. In fact, HomeRF now holds about 95% of this market. HomeRF wireless LAN support high data rates and has sufficient range for full home coverage. The HomeRF standard supports advanced cordless phone features (e.g. up to eight voice channels, call waiting, caller ID, and voice error correction for excellent voice quality). HomeRF has exceptional immunity to interference from other HomeRF networks and from narrow band telecommunication (e.g. AM and FM radio signals). This allows lots of home-sized networks to be packed closely together - an important consideration if everyone's neighbors also have wireless networks. HomeRF has strong data encryption capabilities to help ensure that privacy and security are protected. [8] Wi-Fi wireless technology is focused on the needs of the corporate (so called "Enterprise Information Technology") market. Wi-Fi technology is essentially a wireless replacement for wire-based local area networks. Wi-Fi wireless LAN are easier to set up, less expensive and more portable than wire-based LAN. Wi-Fi networks support high data rates and have a range up to 500 meters. Wi-Fi supports voice communication but lacks advanced cordless phone features [9]. Wireless LAN products include LAN adaptors (provide wireless capabilities for laptops and related devices), access points (the wireless equivalent of a LAN hub that receives, buffers and transmits data between a wireless and wire-based LAN) and LAN bridges (wireless link between wireless LAN). Wi-Fi access points can already be found in some hotels, airports and restaurant chains. A person with a Wi-Fi capable laptop (or related device) in range of an access point can utilize the resources provided by that LAN (e.g. Internet and email). [10] Bluetooth technology is focused on applications that require the unconscious and spontaneous formation of wireless Personal Area Networks (PAN). Bluetooth devices brought into close proximity (typically 10 meters, though up to 100 meters is possible) automatically communicate with each other and establish their respective identities. One Bluetooth device becomes the "master" (controlling communication), and the other devices become "slaves" (their communication is controlled by the master). From two to eight Bluetooth devices can be part of a PAN. [11] Bluetooth technology has been used to develop wireless sensor networks [12]. The Official BlueTooth Website sketches out a number of interesting applications that include: "The three-in-one phone - At home, your phone functions as a portable phone (fixed line charge). When you're on the move, it functions as a mobile phone (cellular charge). And when your phone comes within range of another mobile phone with built-in Bluetooth wireless technology it functions as a walkie-talkie (no telephone charge) [telephone usage charge]." "The Internet bridge - Use your mobile computer to surf the Internet wherever your are, and regardless if you're cordlessly connected through a mobile phone (cellular) or through a wire-bound connection ." "The interactive conference - In meetings and conferences you can transfer selected documents instantly with selected participants, and exchange electronic business cards automatically, without any wired connections." "The ultimate headset - Connect your wireless headset to your mobile phone, mobile computer or any wired connection to keep your hands free for more important tasks when you're at the office or in your car." "The automatic synchronizer -Automatic synchronization of your desktop, mobile computer, notebook (PC-PDA and PC-HPC) [personal digital assistant and hand-held personal computer] and your mobile [cell] phone. For instance, when you enter your office the address list and calendar in your notebook will automatically be updated to agree with the one in your desktop, or vice versa. " [13] Other promising wireless technologies are on the horizon. So-called, ultra-wideband technology (UWB - also called "time domain" communication) is fundamentally different from spread spectrum technology and works by periodically transmitting narrow pulses at wide time intervals [14]. UWB communication may have performance advantages over spread spectrum communication including very low power requirements, small size for both the transmitters and receivers, and superior noise immunity [15]. UWB technology is currently employed for radar imaging systems that can "see" through concrete walls while a radio-locator system is being developed that has military and emergency/rescue (e.g. tracking firefighters) applications [16]. The Federal Communication Commission (FCC) recently evaluated UWB transmitters operating at a center frequency of 2.4 GHz (a frequency of 2.4 billion cycles per second). The FCC study concluded that operating a group of UWB transmitters in close proximity to a Global Positioning System (GPS) receiver was likely to cause interference [17]. This issue needs to be resolved before UWB technology is likely to be used for general wireless applications. [ Top of Page ] Issues to ConsiderThe Need
State-of-the-Practice
Future Technology and Products
[ Top of Page ] References
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