Telephony is the field of technology involving the development and deployment of telecommunication services for the purpose of electronic transmission of voice, fax, or data, between distant parties. The history of telephony is intimately linked to the development of the telephone. Telephony is referred to as the construction or operation of telephones and telephonic systems and as a system of telecommunications in which telephonic equipment is employed in the transmission of speech or other sound between points, with or without the use of wires; the term is used to refer to computer hardware and computer network systems, that perform functions traditionally performed by telephone equipment. In this context the technology is referred to as Internet telephony, or voice over Internet Protocol; the first telephones were connected directly in pairs. Each user had a separate telephone wired to the locations he or she might wish to reach; this became inconvenient and unmanageable when people wanted to communicate with more than a few people.
The inventions of the telephone exchange provided the solution for establishing telephone connections with any other telephone in service in the local area. Each telephone was connected to the exchange via the local loop. Nearby exchanges in other service areas were connected with trunk lines and long distance service could be established by relaying the calls through multiple exchanges. Switchboards were manually operated by an attendant referred to as the "switchboard operator"; when a customer cranked a handle on the telephone, it turned on an indicator on the board in front of the operator, who would plug the operator headset into that jack and offer service. The caller had to ask for the called party by name by number, the operator connected one end of a circuit into the called party jack to alert them. If the called station answered, the operator disconnected their headset and completed the station-to-station circuit. Trunk calls were made with the assistance of other operators at other exchangers in the network.
In modern times, most telephones are plugged into telephone jacks. The jacks are connected by inside wiring to a drop wire. Cables bring a large number of drop wires from all over a district access network to one wire center or telephone exchange; when a telephone user wants to make a telephone call, equipment at the exchange examines the dialed telephone number and connects that telephone line to another in the same wire center, or to a trunk to a distant exchange. Most of the exchanges in the world are interconnected through a system of larger switching systems, forming the public switched telephone network. After the middle of the 20th century and data became important secondary users of the network created to carry voices, late in the century, parts of the network were upgraded with ISDN and DSL to improve handling of such traffic. Today, telephony uses digital technology in the provisioning of telephone systems. Telephone calls can be provided digitally, but may be restricted to cases in which the last mile is digital, or where the conversion between digital and analog signals takes place inside the telephone.
This advancement has reduced costs in communication, improved the quality of voice services. The first implementation of this, ISDN, permitted all data transport from end-to-end speedily over telephone lines; this service was made much less important due to the ability to provide digital services based on the IP protocol. Since the advent of personal computer technology in the 1980s, computer telephony integration has progressively provided more sophisticated telephony services and controlled by the computer, such as making and receiving voice and data calls with telephone directory services and caller identification; the integration of telephony software and computer systems is a major development in the evolution of office automation. The term is used in describing the computerized services of call centers, such as those that direct your phone call to the right department at a business you're calling. It's sometimes used for the ability to use your personal computer to initiate and manage phone calls.
CTI is not a new concept and has been used in the past in large telephone networks, but only dedicated call centers could justify the costs of the required equipment installation. Primary telephone service providers are offering information services such as automatic number identification, a telephone service architecture that separates CTI services from call switching and will make it easier to add new services. Dialed Number Identification Service on a scale is wide enough for its implementation to bring real value to business or residential telephone usage. A new generation of applications is being developed as a result of standardization and availability of low cost computer telephony links. Starting with the introduction of the transistor, invented in 1947 by Bell Laboratories, to amplification and switching circuits in the 1950s, through development of computer-based electronic switching systems, the public switched telephone network has evolved towards automation and digitization of signaling and audio transmissions.
Digital telephony is the use of digital electronics in the operation and provisioning of telephony systems and services. Since the 1960s a digital core network has replaced the traditional analog transmission and signaling systems, much of the access network has been digitized. Digital
Cable television is a system of delivering television programming to consumers via radio frequency signals transmitted through coaxial cables, or in more recent systems, light pulses through fiber-optic cables. This contrasts with broadcast television, in which the television signal is transmitted over the air by radio waves and received by a television antenna attached to the television. FM radio programming, high-speed Internet, telephone services, similar non-television services may be provided through these cables. Analog television was standard in the 20th century, but since the 2000s, cable systems have been upgraded to digital cable operation. A "cable channel" is a television network available via cable television; when available through satellite television, including direct broadcast satellite providers such as DirecTV, Dish Network and Sky, as well as via IPTV providers such as Verizon FIOS and AT&T U-verse is referred to as a "satellite channel". Alternative terms include "non-broadcast channel" or "programming service", the latter being used in legal contexts.
Examples of cable/satellite channels/cable networks available in many countries are HBO, Cinemax, MTV, Cartoon Network, AXN, E!, FX, Discovery Channel, Canal+, Fox Sports, Disney Channel, Nickelodeon, CNN International, ESPN. The abbreviation CATV is used for cable television, it stood for Community Access Television or Community Antenna Television, from cable television's origins in 1948. In areas where over-the-air TV reception was limited by distance from transmitters or mountainous terrain, large "community antennas" were constructed, cable was run from them to individual homes; the origins of cable broadcasting for radio are older as radio programming was distributed by cable in some European cities as far back as 1924. To receive cable television at a given location, cable distribution lines must be available on the local utility poles or underground utility lines. Coaxial cable brings the signal to the customer's building through a service drop, an overhead or underground cable. If the subscriber's building does not have a cable service drop, the cable company will install one.
The standard cable used in the U. S. is RG-6, which has a 75 ohm impedance, connects with a type F connector. The cable company's portion of the wiring ends at a distribution box on the building exterior, built-in cable wiring in the walls distributes the signal to jacks in different rooms to which televisions are connected. Multiple cables to different rooms are split off the incoming cable with a small device called a splitter. There are two standards for cable television. All cable companies in the United States have switched to or are in the course of switching to digital cable television since it was first introduced in the late 1990s. Most cable companies require a set-top box or a slot on one's TV set for conditional access module cards to view their cable channels on newer televisions with digital cable QAM tuners, because most digital cable channels are now encrypted, or "scrambled", to reduce cable service theft. A cable from the jack in the wall is attached to the input of the box, an output cable from the box is attached to the television the RF-IN or composite input on older TVs.
Since the set-top box only decodes the single channel, being watched, each television in the house requires a separate box. Some unencrypted channels traditional over-the-air broadcast networks, can be displayed without a receiver box; the cable company will provide set top boxes based on the level of service a customer purchases, from basic set top boxes with a standard definition picture connected through the standard coaxial connection on the TV, to high-definition wireless DVR receivers connected via HDMI or component. Older analog television sets are "cable ready" and can receive the old analog cable without a set-top box. To receive digital cable channels on an analog television set unencrypted ones, requires a different type of box, a digital television adapter supplied by the cable company. A new distribution method that takes advantage of the low cost high quality DVB distribution to residential areas, uses TV gateways to convert the DVB-C, DVB-C2 stream to IP for distribution of TV over IP network in the home.
In the most common system, multiple television channels are distributed to subscriber residences through a coaxial cable, which comes from a trunkline supported on utility poles originating at the cable company's local distribution facility, called the "headend". Many channels can be transmitted through one coaxial cable by a technique called frequency division multiplexing. At the headend, each television channel is translated to a different frequency. By giving each channel a different frequency "slot" on the cable, the separate television signals do not interfere with each other. At an outdoor cable box on the subscriber's residence the company's service drop cable is connected to cables distributing the signal to different rooms in the building. At each television, the subscriber's television or a set-top box provided by the cable company translates the desired channel back to its original frequency, it is displayed onscreen. Due to widespread cable theft in earlier analog systems, the signals are encrypted on m
In telephony, the demarcation point is the point at which the public switched telephone network ends and connects with the customer's on-premises wiring. It is the dividing line which determines, responsible for installation and maintenance of wiring and equipment—customer/subscriber, or telephone company/provider; the demarcation point has changed over time. Demarcation point is sometimes DMARC, or similar; the term MPOE is synonymous, with the added implication that it occurs as soon as possible upon entering the customer premises. A network interface device serves as the demarcation point. Prior to the Bell System divestiture on January 1, 1984, American Telephone & Telegraph Company through its Bell System companies held a natural monopoly for telephone service within the United States and Canada. AT&T owned the local loop, including the telephone wiring within the customer premises and the customer telephone equipment. A similar arrangement existed with smaller, regional telephone companies such as GTE.
As a result of deregulation of the telephone system, unbundling of the local loop, lawsuits by companies wishing to sell third-party equipment to connect to the telephone network, there was a need to delineate the portion of the network, owned by the customer and the portion owned by the telephone company or the common carrier. Where the portions meet is called the demarcation point; the demarcation point varies from building service level. In its simplest form, the demarcation point is a junction block where telephone extensions join to connect to the network; this junction block includes a lightning arrester. In multi-line installations such as businesses or apartment buildings, the demarcation point may be a punch down block. In most places this hardware existed before deregulation. In the United States, the modern demarcation point is a device defined by FCC rules to allow safe connection of third-party telephone customer-premises equipment and wiring to the Public Switched Telephone Network.
The modern demarcation point is the network interface device or intelligent network interface device known as a "smartjack". The NID is the telco's property; the NID may be indoors. The NID is placed for easy access by a technician, it contains a lightning arrestor and test circuitry which allows the carrier to remotely test whether a wiring fault lies in the customer premises or in the carrier wiring, without requiring a technician at the premises. The demarcation point has a user accessible RJ-11 jack, connected directly to the telephone network, a small loop of telephone cord connecting to the jack by a modular connector; when the loop is disconnected, the on-premises wiring is isolated from the telephone network and the customer may directly connect a telephone to the network via the jack to assist in determining the location of a wiring fault. In most cases, everything from the central office to and including the demarcation point is owned by the carrier and everything past it is owned by the property owner.
As the local loop becomes upgraded, with fiber optic and coaxial cable technologies sometimes replacing the original unshielded twisted pair to the premises, the demarcation point has grown to incorporate the equipment necessary to interface the original premises POTS wiring and equipment to the new communication channel. Demarcation points on houses built prior to the Bell System divestiture do not contain a test jack, they only contained a spark-gap surge protector, a grounding post and mount point to connect a single telephone line. The second wire pair was left unconnected and were kept as a spare pair in case the first pair was damaged. DEMARCs that handle both telephony and IT fiber optic internet lines do not look like the ones pictured above. In many places several customers share one central DEMARC for a strip mall setting. A DEMARC will be located indoors if it is serving more than a single customer; this may impede access. Outdoor ones provide easier access, without disturbing other tenants, but call for weatherproofing and punching through a wall for each new addition of wires and service.
Indoor DEMARC's will be identified by a patch panel of telephone wires on the wall next to a series of boxes with RJ48 jacks for T-1 lines. Each business or individual customer can expect their own separate box for internet access T-1 lines. A demarcation point extension, or demarc extension is the transmission path originating from the interface of the access provider's side of a demarcation point within a premises and ending at the termination point prior to the interface of the edge Customer Premises Equipment; this may include in-segment equipment, media converters and patch cords as required to complete the circuit's transmission path to the edge CPE. A demarc extension is more termed "Service Interface Extension", may be referred to as inside wiring, extended demarc, circuit extension, CPE cabling, riser cabling or DMARC extension. A demarc extension became an important factor to consider in a building's telecommunications infrastructure after the 1984 deregulation of AT&T as well as the supplemental FCC rulings of 1991, 1996 and 1997.
Preceding these rulings, the Bell System Companies held a monopoly and did not allow an interconnection with third party equipment. The incumbent local exchange carriers and other local access providers are now mandated by federal law to provide a point where the operational control or ownersh
Electronic filters are circuits which perform signal processing functions to remove unwanted frequency components from the signal, to enhance wanted ones, or both. Electronic filters can be: passive or active analog or digital high-pass, low-pass, band-pass, band-stop, or all-pass. Discrete-time or continuous-time linear or non-linear infinite impulse response or finite impulse response The most common types of electronic filters are linear filters, regardless of other aspects of their design. See the article on linear filters for details on their design and analysis; the oldest forms of electronic filters are passive analog linear filters, constructed using only resistors and capacitors or resistors and inductors. These are known as RL single-pole filters respectively. However, these simple filters have limited uses. Multipole LC filters provide greater control of response form and transition bands; the first of these filters was the constant k filter, invented by George Campbell in 1910. Campbell's filter was a ladder network based on transmission line theory.
Together with improved filters by Otto Zobel and others, these filters are known as image parameter filters. A major step forward was taken by Wilhelm Cauer who founded the field of network synthesis around the time of World War II. Cauer's theory allowed filters to be constructed that followed some prescribed frequency function. Passive implementations of linear filters are based on combinations of resistors and capacitors; these types are collectively known as passive filters, because they do not depend upon an external power supply and/or they do not contain active components such as transistors. Inductors block high-frequency signals and conduct low-frequency signals, while capacitors do the reverse. A filter in which the signal passes through an inductor, or in which a capacitor provides a path to ground, presents less attenuation to low-frequency signals than high-frequency signals and is therefore a low-pass filter. If the signal passes through a capacitor, or has a path to ground through an inductor the filter presents less attenuation to high-frequency signals than low-frequency signals and therefore is a high-pass filter.
Resistors on their own have no frequency-selective properties, but are added to inductors and capacitors to determine the time-constants of the circuit, therefore the frequencies to which it responds. The inductors and capacitors are the reactive elements of the filter; the number of elements determines the order of the filter. In this context, an LC tuned circuit being used in a band-pass or band-stop filter is considered a single element though it consists of two components. At high frequencies, sometimes the inductors consist of single loops or strips of sheet metal, the capacitors consist of adjacent strips of metal; these inductive or capacitive pieces of metal are called stubs. The simplest passive filters, RC and RL filters, include only one reactive element, except hybrid LC filter, characterized by inductance and capacitance integrated in one element. An L filter consists of one in series and one in parallel. Three-element filters can have a'T' or'π' topology and in either geometries, a low-pass, high-pass, band-pass, or band-stop characteristic is possible.
The components can be chosen symmetric or not, depending on the required frequency characteristics. The high-pass T filter in the illustration, has a low impedance at high frequencies, a high impedance at low frequencies; that means that it can be inserted in a transmission line, resulting in the high frequencies being passed and low frequencies being reflected. For the illustrated low-pass π filter, the circuit can be connected to a transmission line, transmitting low frequencies and reflecting high frequencies. Using m-derived filter sections with correct termination impedances, the input impedance can be reasonably constant in the pass band. Multiple element filters are constructed as a ladder network; these can be seen as a continuation of the L, π designs of filters. More elements are needed when it is desired to improve some parameter of the filter such as stop-band rejection or slope of transition from pass-band to stop-band. Active filters are implemented using a combination of passive and active components, require an outside power source.
Operational amplifiers are used in active filter designs. These can have high Q factor, can achieve resonance without the use of inductors. However, their upper frequency limit is limited by the bandwidth of the amplifiers. There are many filter technologies other than lumped component electronics; these include digital filters, crystal filters, mechanical filters, surface acoustic wave filters, bulk acoustic wave filters, garnet filters, atomic filters. See Filter for further analysisThe transfer function H of a filter is the ratio of the output signal Y to that of the input signal X as a function of the complex frequency s: H = Y X with s = σ + j ω; the transfer function of all linear time-invariant filt
Digital television is the transmission of television signals, including the sound channel, using digital encoding, in contrast to the earlier television technology, analog television, in which the video and audio are carried by analog signals. It is an innovative advance that represents the first significant evolution in television technology since color television in the 1950s. Digital TV transmits in a new image format called HDTV, with greater resolution than analog TV, in a wide screen aspect ratio similar to recent movies in contrast to the narrower screen of analog TV, it makes more economical use of scarce radio spectrum space. A transition from analog to digital broadcasting began around 2006 in some countries, many industrial countries have now completed the changeover, while other countries are in various stages of adaptation. Different digital television broadcasting standards have been adopted in different parts of the world; this standard has been adopted in Europe, Asia, total about 60 countries.
Advanced Television System Committee uses eight-level vestigial sideband for terrestrial broadcasting. This standard has been adopted by 6 countries: United States, Mexico, South Korea, Dominican Republic and Honduras. Integrated Services Digital Broadcasting is a system designed to provide good reception to fixed receivers and portable or mobile receivers, it utilizes two-dimensional interleaving. It supports hierarchical transmission of up to three layers and uses MPEG-2 video and Advanced Audio Coding; this standard has been adopted in Japan and the Philippines. ISDB-T International is an adaptation of this standard using H.264/MPEG-4 AVC that been adopted in most of South America and is being embraced by Portuguese-speaking African countries. Digital Terrestrial Multimedia Broadcasting adopts time-domain synchronous OFDM technology with a pseudo-random signal frame to serve as the guard interval of the OFDM block and the training symbol; the DTMB standard has been adopted in the People's Republic including Hong Kong and Macau.
Digital Multimedia Broadcasting is a digital radio transmission technology developed in South Korea as part of the national IT project for sending multimedia such as TV, radio and datacasting to mobile devices such as mobile phones, laptops and GPS navigation systems. Digital TV's roots have been tied closely to the availability of inexpensive, high performance computers, it wasn't until the 1990s. In the mid-1980s, as Japanese consumer electronics firms forged ahead with the development of HDTV technology, as the MUSE analog format was proposed by Japan's public broadcaster NHK as a worldwide standard, Japanese advancements were seen as pacesetters that threatened to eclipse U. S. electronics companies. Until June 1990, the Japanese MUSE standard—based on an analog system—was the front-runner among the more than 23 different technical concepts under consideration. An American company, General Instrument, demonstrated the feasibility of a digital television signal; this breakthrough was of such significance that the FCC was persuaded to delay its decision on an ATV standard until a digitally based standard could be developed.
In March 1990, when it became clear that a digital standard was feasible, the FCC made a number of critical decisions. First, the Commission declared that the new ATV standard must be more than an enhanced analog signal, but be able to provide a genuine HDTV signal with at least twice the resolution of existing television images. To ensure that viewers who did not wish to buy a new digital television set could continue to receive conventional television broadcasts, it dictated that the new ATV standard must be capable of being "simulcast" on different channels; the new ATV standard allowed the new DTV signal to be based on new design principles. Although incompatible with the existing NTSC standard, the new DTV standard would be able to incorporate many improvements; the final standard adopted by the FCC did not require a single standard for scanning formats, aspect ratios, or lines of resolution. This outcome resulted from a dispute between the consumer electronics industry and the computer industry over which of the two scanning processes—interlaced or progressive—is superior.
Interlaced scanning, used in televisions worldwide, scans even-numbered lines first odd-numbered ones. Progressive scanning, the format used in computers, scans lines in sequences, from top to bottom; the computer industry argued that progressive scanning is superior because it does not "flicker" in the manner of interlaced scanning. It argued that progressive scanning enables easier connections with the Internet, is more cheaply converted to interlaced formats than vice versa; the film industry supported progressive scanning because it offers a more efficient means of converting filmed programming into digital formats. For their part, the consumer electronics industry and broadcasters argued that interlaced scanning was the only technology that could transmit the highest quality pictures feasible, i.e. 1,080 lines per picture and 1,920 pixels per line. Broadcasters favored interlaced scanning because their vast archive of interlaced
Electric power distribution
Electric power distribution is the final stage in the delivery of electric power. Distribution substations connect to the transmission system and lower the transmission voltage to medium voltage ranging between 2 kV and 35 kV with the use of transformers. Primary distribution lines carry this medium voltage power to distribution transformers located near the customer's premises. Distribution transformers again lower the voltage to the utilization voltage used by lighting, industrial equipment or household appliances. Several customers are supplied from one transformer through secondary distribution lines. Commercial and residential customers are connected to the secondary distribution lines through service drops. Customers demanding a much larger amount of power may be connected directly to the primary distribution level or the subtransmission level; the transition from transmission to distribution happens in a power substation, which has the following functions:Circuit breakers and switches enable the substation to be disconnected from the transmission grid or for distribution lines to be disconnected.
Transformers step down 35 kV or more, down to primary distribution voltages. These are medium voltage circuits 600-35,000 V. From the transformer, power goes to the busbar that can split the distribution power off in multiple directions; the bus distributes power to distribution lines. Urban distribution is underground, sometimes in common utility ducts. Rural distribution is above ground with utility poles, suburban distribution is a mix. Closer to the customer, a distribution transformer steps the primary distribution power down to a low-voltage secondary circuit 120/240 V in the US for residential customers; the power comes to the customer via an electricity meter. The final circuit in an urban system may be less than 50 feet, but may be over 300 feet feet for a rural customer. Electric power distribution became necessary only in the 1880s when electricity started being generated at power stations. Before that electricity was generated where it was used; the first power distribution systems installed in European and US cities were used to supply lighting: arc lighting running on high voltage alternating current or direct current, incandescent lighting running on low voltage direct current.
Both were supplanting gas lighting systems, with arc lighting taking over large area and street lighting, incandescent lighting replacing gas for business and residential lighting. Due to the high voltages used in arc lighting, a single generating station could supply a long string of lights, up to 7-mile long circuits; each doubling of the voltage would allow the same size cable to transmit the same amount of power four times the distance for a given power loss. Direct current indoor incandescent lighting systems, for example the first Edison Pearl Street Station installed in 1882, had difficulty supplying customers more than a mile away; this was due to the low 110 volt system being used throughout the system, from the generators to the final use. The Edison DC system needed thick copper conductor cables, the generating plants needed to be within about 1.5 miles of the farthest customer to avoid excessively large and expensive conductors. Transmitting electricity a long distance at high voltage and reducing it to a lower voltage for lighting became a recognized engineering roadblock to electric power distribution with many, not satisfactory, solutions tested by lighting companies.
The mid-1880s saw a breakthrough with the development of functional transformers that allowed the AC voltage to be "stepped up" to much higher transmission voltages and dropped down to a lower end user voltage. With much cheaper transmission costs and the greater economies of scale of having large generating plants supply whole cities and regions, the use of AC spread rapidly. In the US the competition between direct current and alternating current took a personal turn in the late 1880s in the form of a "War of Currents" when Thomas Edison started attacking George Westinghouse and his development of the first US AC transformer systems, pointing out all the deaths caused by high voltage AC systems over the years and claiming any AC system was inherently dangerous. Edison's propaganda campaign was short lived with his company switching over to AC in 1892. AC became the dominant form of transmission of power with innovations in Europe and the US in electric motor designs and the development of engineered universal systems allowing the large number of legacy systems to be connected to large AC grids.
In the first half of the 20th century, in many places the electric power industry was vertically integrated, meaning that one company did generation, distribution and billing. Starting in the 1970s and 1980s, nations began the process of deregulation and privatisation, leading to electricity markets; the distribution system would remain regulated, but generation and sometimes transmission systems were transformed into competitive markets. Electric power begins at a generating station, where the potential difference can be as high as 33,000 volts. AC is used. Users of large amounts of DC power such as some railway electrification systems, telephone exchanges and industrial processes such as aluminium smelting use rectifiers to derive DC from the public AC supply, or may have their own generation systems. High-voltage DC can be advantageous for isolating alternating-current systems or controlling the quantity of electricity transmitted. For example, Hydro-Québec has a direct-current line which g
A building, or edifice, is a structure with a roof and walls standing more or less permanently in one place, such as a house or factory. Buildings come in a variety of sizes and functions, have been adapted throughout history for a wide number of factors, from building materials available, to weather conditions, land prices, ground conditions, specific uses, aesthetic reasons. To better understand the term building compare the list of nonbuilding structures. Buildings serve several societal needs – as shelter from weather, living space, privacy, to store belongings, to comfortably live and work. A building as a shelter represents a physical division of the outside. Since the first cave paintings, buildings have become objects or canvasses of much artistic expression. In recent years, interest in sustainable planning and building practices has become an intentional part of the design process of many new buildings; the word building is the act of making it. As a noun, a building is'a structure that has a roof and walls and stands more or less permanently in one place'.
In the broadest interpretation a fence or wall is a building. However, the word structure is used more broadly than building including natural and man-made formations and does not have walls. Structure is more to be used for a fence. Sturgis' Dictionary included that " differs from architecture in excluding all idea of artistic treatment; as a verb, building is the act of construction. Structural height in technical usage is the height to the highest architectural detail on building from street-level. Depending on how they are classified and masts may or may not be included in this height. Spires and masts used as antennas are not included; the definition of a low-rise vs. a high-rise building is a matter of debate, but three storeys or less is considered low-rise. A report by Shinichi Fujimura of a shelter built 500 000 years ago is doubtful since Fujimura was found to have faked many of his findings. Supposed remains of huts found at the Terra Amata site in Nice purportedly dating from 200 000 to 400 000 years ago have been called into question.
There is clear evidence of homebuilding from around 18 000 BC. Buildings became common during the Neolithic. Single-family residential buildings are most called houses or homes. Multi-family residential buildings containing more than one dwelling unit are called a duplex or an apartment building. A condominium is an apartment rather than rents. Houses may be built in pairs, in terraces where all but two of the houses have others either side. Houses which were built as a single dwelling may be divided into apartments or bedsitters. Building types may range from huts to multimillion-dollar high-rise apartment blocks able to house thousands of people. Increasing settlement density in buildings is a response to high ground prices resulting from many people wanting to live close to work or similar attractors. Other common building materials are concrete or combinations of either of these with stone. Residential buildings have different names for their use depending if they are seasonal include holiday cottage or timeshare.
If the residents are in need of special care such as a nursing home, orphanage or prison. Many people lived in communal buildings called longhouses, smaller dwellings called pit-houses and houses combined with barns sometimes called housebarns. Buildings are defined to be substantial, permanent structures so other dwelling forms such as houseboats and motorhomes are dwellings but not buildings. Sometimes a group of inter-related builds are referred to as a complex – for example a housing complex, educational complex, hospital complex, etc; the practice of designing and operating buildings is most a collective effort of different groups of professionals and trades. Depending on the size and purpose of a particular building project, the project team may include: A real estate developer who secures funding for the project. Other possible design Engineer specialists may be involved such as Fire, facade engineers, building physics, Telecomms, AV (Audio V