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Fixed Wireless
Fixed wireless is the operation of wireless communication devices or systems used to connect two fixed locations (e.g., building to building or tower to building) with a radio or other wireless link, such as laser bridge. Usually, fixed wireless is part of a wireless LAN infrastructure. The purpose of a fixed wireless link is to enable data communications between the two sites or buildings. Fixed wireless data (FWD) links are often a cost-effective alternative to leasing fiber or installing cables between the buildings. The point-to-point signal transmissions occur through the air over a terrestrial microwave platform rather than through copper or optical fiber; therefore, fixed wireless does not require satellite feeds or local telephone service. The advantages of fixed wireless include the ability to connect with users in remote areas without the need for laying new cables and the capacity for broad bandwidth that is not impeded by fiber or cable capacities. Fixed wire ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Public Utility
A public utility company (usually just utility) is an organization that maintains the infrastructure for a public service (often also providing a service using that infrastructure). Public utilities are subject to forms of public control and regulation ranging from local community-based groups to statewide government monopolies. Public utilities are meant to supply goods/services that are considered essential; water, gas, electricity, telephone, and other communication systems represent much of the public utility market. The transmission lines used in the transportation of electricity, or natural gas pipelines, have natural monopoly characteristics. If the infrastructure already exists in a given area, minimal benefit is gained through competing. In other words, these industries are characterized by ''economies of scale'' in production. There are many different types of public utilities. Some, especially large companies, offer multiple products, such as electricity and na ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ethernet Bridge
A network bridge is a computer networking device that creates a single, aggregate network from multiple communication networks or network segments. This function is called network bridging. Bridging is distinct from routing. Routing allows multiple networks to communicate independently and yet remain separate, whereas bridging connects two separate networks as if they were a single network. In the OSI model, bridging is performed in the data link layer (layer 2). If one or more segments of the bridged network are wireless, the device is known as a wireless bridge. The main types of network bridging technologies are simple bridging, multiport bridging, and learning or transparent bridging. Transparent bridging Transparent bridging uses a table called the forwarding information base to control the forwarding of frames between network segments. The table starts empty and entries are added as the bridge receives frames. If a destination address entry is not found in the table, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microwave Bypass
Microwave Bypass, Inc. launched the world's first fixed wireless internet access technology in 1987, a decade before Wi-Fi. It enabled local and remote networks to connect at the then full Ethernet (802.3) data rate of 10 megabits per second, and for up to 4.3 miles. The company was founded in March 1986 by David Theodore (25), operating from One Kendall Square, Cambridge, Massachusetts. Its wireless solution consisted of a modified broadcast quality video radio (23 GHz) coupled with Microwave Bypass' EtherWave Transceiver. The system met the then highest Ethernet throughput and could transmit , in keeping with Ethernet's propagation delay allowance (46.4µs). Beta testing occurred at Massachusetts General Hospital in March 1987, at the invitation of network manager, David Murphy, and with Network World's Laura DiDio and representatives of Harvard University and Boston University's Dr. Mikhail Orlov in attendance. After a successful demo the first two production links were ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mobile Broadband
Mobile broadband is the marketing term for wireless Internet access via mobile networks. Access to the network can be made through a portable modem, wireless modem, or a tablet/ smartphone (possibly tethered) or other mobile device. The first wireless Internet access became available in 1991 as part of the second generation (2G) of mobile phone technology. Higher speeds became available in 2001 and 2006 as part of the third (3G) and fourth (4G) generations. In 2011, 90% of the world's population lived in areas with 2G coverage, while 45% lived in areas with 2G and 3G coverage."The World in 2011: ITC Facts and Figures" International Telecommunication Union (ITU), Geneva, 2011 Mobile broadband uses the spectrum of 225 |
Mobile Wireless Communication
A mobile phone, cellular phone, cell phone, cellphone, handphone, hand phone or pocket phone, sometimes shortened to simply mobile, cell, or just phone, is a portable telephone that can make and receive calls over a radio frequency link while the user is moving within a telephone service area. The radio frequency link establishes a connection to the switching systems of a mobile phone operator, which provides access to the public switched telephone network (PSTN). Modern mobile telephone services use a cellular network architecture and, therefore, mobile telephones are called ''cellular telephones'' or ''cell phones'' in North America. In addition to telephony, digital mobile phones ( 2G) support a variety of other services, such as text messaging, multimedia messagIng, email, Internet access, short-range wireless communications (infrared, Bluetooth), business applications, video games and digital photography. Mobile phones offering only those capabilities are known as featur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Internet Access
Internet access is the ability of individuals and organizations to connect to the Internet using computer terminals, computers, and other devices; and to access services such as email and the World Wide Web. Internet access is sold by Internet service providers (ISPs) delivering connectivity at a wide range of data transfer rates via various networking technologies. Many organizations, including a growing number of municipal entities, also provide cost-free wireless access and landlines. Availability of Internet access was once limited, but has grown rapidly. In 1995, only percent of the world's population had access, with well over half of those living in the United States, and consumer use was through dial-up. By the first decade of the 21st century, many consumers in developed nations used faster broadband technology, and by 2014, 41 percent of the world's population had access, broadband was almost ubiquitous worldwide, and global average connection speeds exceeded one ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Layer 2
The data link layer, or layer 2, is the second layer of the seven-layer OSI model of computer networking. This layer is the protocol layer that transfers data between nodes on a network segment across the physical layer. The data link layer provides the functional and procedural means to transfer data between network entities and may also provide the means to detect and possibly correct errors that can occur in the physical layer. The data link layer is concerned with local delivery of frames between nodes on the same level of the network. Data-link frames, as these protocol data units are called, do not cross the boundaries of a local area network. Inter-network routing and global addressing are higher-layer functions, allowing data-link protocols to focus on local delivery, addressing, and media arbitration. In this way, the data link layer is analogous to a neighborhood traffic cop; it endeavors to arbitrate between parties contending for access to a medium, without c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ISM Band
The ISM radio bands are portions of the radio spectrum reserved internationally for industrial, scientific and medical (ISM) purposes, excluding applications in telecommunications. Examples of applications for the use of radio frequency (RF) energy in these bands include radio-frequency process heating, microwave ovens, and medical diathermy machines. The powerful emissions of these devices can create electromagnetic interference and disrupt radio communication using the same frequency, so these devices are limited to certain bands of frequencies. In general, communications equipment operating in ISM bands must tolerate any interference generated by ISM applications, and users have no regulatory protection from ISM device operation in these bands. Despite the intent of the original allocations, in recent years the fastest-growing use of these bands has been for short-range, low power wireless communications systems, since these bands are often approved for such devices, which ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wi-Fi
Wi-Fi () is a family of wireless network protocols, based on the IEEE 802.11 family of standards, which are commonly used for local area networking of devices and Internet access, allowing nearby digital devices to exchange data by radio waves. These are the most widely used computer networks in the world, used globally in home and small office networks to link desktop and laptop computers, tablet computers, smartphones, smart TVs, printers, and smart speakers together and to a wireless router to connect them to the Internet, and in wireless access points in public places like coffee shops, hotels, libraries and airports to provide visitors with Internet access for their mobile devices. ''Wi-Fi'' is a trademark of the non-profit Wi-Fi Alliance, which restricts the use of the term ''Wi-Fi Certified'' to products that successfully complete interoperability certification testing. the Wi-Fi Alliance consisted of more than 800 companies from around the world. over 3.05 billion W ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Battery (electricity)
An electric battery is a source of electric power consisting of one or more electrochemical cells with external connections for powering electrical devices. When a battery is supplying power, its positive terminal is the cathode and its negative terminal is the anode. The terminal marked negative is the source of electrons that will flow through an external electric circuit to the positive terminal. When a battery is connected to an external electric load, a redox reaction converts high-energy reactants to lower-energy products, and the free-energy difference is delivered to the external circuit as electrical energy. Historically the term "battery" specifically referred to a device composed of multiple cells; however, the usage has evolved to include devices composed of a single cell. Primary (single-use or "disposable") batteries are used once and discarded, as the electrode materials are irreversibly changed during discharge; a common example is the alkaline battery use ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bandwidth (computing)
In computing, bandwidth is the maximum rate of data transfer across a given path. Bandwidth may be characterized as network bandwidth, data bandwidth, or digital bandwidth. This definition of ''bandwidth'' is in contrast to the field of signal processing, wireless communications, modem data transmission, digital communications, and electronics, in which ''bandwidth'' is used to refer to analog signal bandwidth measured in hertz, meaning the frequency range between lowest and highest attainable frequency while meeting a well-defined impairment level in signal power. The actual bit rate that can be achieved depends not only on the signal bandwidth but also on the noise on the channel. Network capacity The term ''bandwidth'' sometimes defines the net bit rate 'peak bit rate', 'information rate,' or physical layer 'useful bit rate', channel capacity, or the maximum throughput of a logical or physical communication path in a digital communication system. For example, bandwidth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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