US 6012101 Computer network having commonly located computing systems
ABSTRACT – A computer network comprised of a plurality of interconnected nodes, each having a DTE device coupled thereto. Plural ones of the DTE devices are each further comprised of a computing system positioned at a first location and a human interface, which includes a video monitor, and plural I/O devices, specifically, a keyboard, mouse and printer, positioned at a second location remotely located relative to the first location. The first locations at which the computing systems of the DTE devices are positioned are commonly located. The DTE devices further include a first encoder coupled to the computing system, a first decoder coupled to the video monitor and the at least one I/O device and a transmission line which couples the encoder to the decoder. The first encoder receives, from the computing system, a video signal to be transmitted to the video monitor and a non-video signal to be transmitted to the at least one I/O device. The first encoder combines the video and the non-video signals into a combined signal and transmits the combined signal to the first decoder via the transmission line. The first decoder receives the combined signal, separates the video and non-video signals therefrom for respective propagation to the video monitor and the at least one I/O device.
The invention relates generally to computer networks and, more particularly, to a computer network which includes plural commonly located computing systems as a portion thereof.
BACKGROUND OF THE INVENTION
In its broadest sense, a computer network is a set of nodes and communication channels which interconnect the set of nodes. The nodes may be computers, terminals, workstations, or communication units of various kinds and may be distributed at different locations. They communicate over the communication channels which are provided by the owner of the computer network or leased from a common carrier. These communication channels may use a variety of transmission media such as optical fibers, coaxial cable or twisted copper pairs. A local area network (or “LAN”) is a computer network at a single site and, in many cases, is confined to a single building. A wide area network (or “WAN”) is a computer network that uses either a public or private switching system to interconnect computers located at plural sites which may be separated by hundreds or thousands of miles.
There are a number of advantages to constructing a computer network. They include resource and data sharing, and communication and data exchange. Resource sharing provides users with convenient access to special computing resources, regardless of their physical location. Data sharing provides users with access to common databases. Data exchanges enable users to exchange data files while communication exchanges enable users to exchange messages, for example, via electronic mail (or “E-mail”). While networks may be arranged in a variety of configurations, a commonly used network design has a bus (also known as a “linear”) topology in which a single network cable is routed through those locations where a data terminal equipment (or “DTE”) device is to be connected to the network. At each of these locations, a physical connection (or “tap”) is made to the cable to allow the DTE at that location to access the network. At selected nodes of such a network, file servers or other large scale computer systems provide network services while, at others of the nodes, individual workstations, each typically comprised of a personal computer (or “PC”), desktop computer, or other type of physically compact computer system capable of both operating as a standalone computer and accessing the network services, reside.
The components of PCs (as well as all other computer systems, including minicomputers and mainframes), may be divided into two functional units–the computing system and the human interface (or “HI”) to the computing system For a PC, the computing system is, quite simply, the chassis which holds the motherboard, power supply, hard drive and the like. The human interface, on the other hand, are those devices that humans use to transfer information to and/or receive information from the computing system. The most commonly recognized devices which form part of the human interface with the computing system include the monitor, keyboard, mouse and printer. Of course, a variety of other devices, for example, a joystick, trackball, touchpad or others too numerous to specifically mention, may form part of the human interface. For most PCs installed at workstations, the computer monitor, keyboard and mouse rest on the desktop while the computer chassis which holds the computing system rests on the floor underneath the desktop.
While the above-described network configuration is quite common in many business establishments, recently, a number of issues, in particular, security concerns, have been raised in connection with such network designs. Business contacts, vendor information, contracts, reports, compilations, proprietary software, access codes, protocols, correspondence, account records, business plans are just some of the fundamental assets of a company which are oftentimes accessible from an employee’s computer where it can be quickly copied onto a floppy disk and stolen.
Disk and CD drives may also be used to introduce illegal, inappropriate or dangerous software to a computer. Storing bootlegged software can expose a company to copyright infringement claims. Computer games often reduce employee productivity. If imported onto a computer system, computer pornography may create a hostile work environment which leads to a sexual discrimination lawsuit against the company. Computer viruses can cause the loss of critical information stored on a computer. Finally, the computing system itself may be damaged or otherwise misconfigured when left accessible to technically oriented employees who take it upon themselves to attempt to repair and/or modify the computer system.
Another concern often raised in connection with the present practice of placing the computer system at the desktop is that such workstation designs actual work against proper maintenance of the computing system. When placed underneath the desktop, computing systems are often forced to absorb physical shocks when accidentally kicked, knocked over or struck by falling objects, any of which could result in damage to the various electronic components, located within the chassis, which comprises the computing system. Oftentimes, a computing system is placed in a “convenient” location and not in a location designed to keep it cool. A computer system typically includes a cyclonic fan designed to direct a constant flow of cooling area at the heat-generating components of the computing system. However, if a barrier is placed a few inches in front of the fan intake, the efficiency of the fan is reduced dramatically. Similarly, placing the computer system against a wall or running cables in front of the fan adversely affects the ability of the fan to properly cool the computing system. Finally, even in relatively clean office environments, the fan tends to draw in dirt and other dust particles into the interior of the computer chassis where they are deposited on the heat-generating electronic components which comprise the computing system. As dust tends to insulate the components on which it is deposited, the ability of such components to dissipate heat becomes degraded when a layer of dust collects on the component.
Logistical support, too, becomes a vexing problem for computer-intensive organizations when computing systems are scattered throughout a facility. When machine failures occur, the repair person must go to the machine to diagnose and repair the machine. Oftentimes, this entails multiple visits to the machine’s location, particularly when the first examination reveals that replacement parts or a replacement machine are needed. Similarly, software upgrades and other performance checks become quite time-consuming tasks when personnel must travel to each machine where the software resides locally.
Finally, many office buildings were designed before the advent of the age of the PC. As a single PC can consume over 300 watts of power, a heavily computerized workplace could potentially demand power in excess of the amount available. Similarly, the heat generated by the large number of computers installed in modern workplaces can easily overwhelm the air conditioning capacity of a building’s HVAC system, thereby causing room temperatures to rise above those levels preferred by the occupants of the building.
These concerns have been driving the development of the network computer (or “NC”) and other so-called “thin” computer solutions. While various NC designs have been proposed, most entail removal of the auxiliary memory (also known as the hard drive) and substantially reducing the size of the processor. All software applications and data files would be stored on the network and the NC would be limited to accesses of network software and data files. Most NC designs also propose that all disk drives (typically, the CD and floppy drives) be removed, thereby eliminating the ability of the NC user to import or export software applications and/or data files.
The development of the NC is, in part due to a recognition by the computer industry of security and other problems which have arisen due to the evolution of computer networks into their present configuration. However, the NC is not a fully satisfactory solution to these problems. While removing much of the processing capability from the workstation, most NC designs propose leaving sufficient intelligence at the workstation to access the internet, load software applications retrieved from the network memory and perform other operations. Thus, while reduced in complexity, NCs will still have maintenance, power and cooling concerns. Thus, while the NC represents a step in the right direction, many of the aforementioned issues cannot be resolved by wide-scale implementation of NCs.
In order to fully resolve the aforementioned issues, the entire computing system needs to be physically separated from the human interface, specifically, by keeping the human interface (monitor, keyboard, mouse and printer) at the workstation while relocating the associated computing system (chassis holding the motherboard, power supply, memory, disk drives, etc.) to a secured computer room where plural computing systems are maintained. By securing the computing systems in one room, the employer’s control over the computer systems would be greatly enhanced. For example, since employees would no longer have personal access, through the floppy or CD drive, to the memory subsystem, employees could not surreptitiously remove information from their computing system. Nor could the employee independently load software or other data files onto their computing system. Similarly, the employee could no longer physically change settings or otherwise modify the hardware portion of the computer. Maintenance would be greatly facilitated by placement of all of the computing systems in a common room. For example, the repair technicians and their equipment could be stationed in the same room with all of the computing systems. Thus, a technician could replace failed components or even swap out the entire unit without making repeated trips to the location of the malfunctioning machine. Such a room could be provided with special HVAC and power systems to ensure that the room is kept clean, cool and fully powered.
Therefore, what is needed is a computer network comprised of plural computers, each configured such that a human interface portion thereof is remotely located relative to a computing system portion thereof, in which plural computing systems are located at a common location.
SUMMARY OF THE INVENTION
In one embodiment, the present invention is of a computer network comprised of a plurality of interconnected nodes, each having a DTE device coupled thereto. At least one, and preferably, plural ones, of the DTE devices are each further comprised of a computing system positioned at a first location, preferably common to the plural computing systems, and a human interface positioned at a second location remotely located relative to the first location. A 4-wire cable couples first and second interface devices which, in turn, are respectively coupled to the computing system and the human interface. The first interface device converts signals generated by the computing system into a format suitable for transmission to the second interface device while the second interface device converts signals, received from the first interface device into a format suitable for transmission to the human interface. In alternate aspects thereof, the computer network may further include a cable, preferably, a thin wire coaxial cable, for interconnecting the plural nodes, the computing system may be a computer chassis and at least one computing system component housed therein and coupled to the first interface device and the human interface may be a video monitor, printer, keyboard or mouse coupled to the second interface device.
In another embodiment, the present invention is of a computer network comprised of a plurality of interconnected nodes, each having a DTE device coupled thereto. At least one, and preferably, plural ones, of the DTE devices are each further comprised of a computing system positioned at a first location, preferably common to the plural computing systems, and a human interface, which includes a video monitor and at least one I/O device, positioned at a second location remotely located relative to the first location. The DTE device further includes a first encoder coupled to the computing system, a first decoder coupled to the video monitor and the at least one I/O device and a transmission line which couples the encoder to the decoder. The first encoder receives, from the computing system, a video signal to be transmitted to the video monitor and a non-video signal to be transmitted to the at least one I/O device. The first encoder combines the video and the non-video signals into a combined signal and transmits the combined signal to the first decoder via the transmission line. The first decoder receives the combined signal, separates the video and non-video signals therefrom for respective propagation to the video monitor and the at least one I/O device.
In one aspect thereof, the computer may further include a second encoder coupled to the computing system and the first encoder and a second decoder coupled to the first decoder and the I/O devices. The second encoder receives a first non-video signal to be transmitted to a first I/O device, a second non-video signal to be transmitted to a second I/O device and a third non-video signal to be transmitted to a third I/O device and combines the first, second and third non-video signals into the non-video signal. The second decoder receives the non-video signal from the first decoder and separates the first, second and third non-video signals therefrom for respective propagation to the first, second and third I/O devices. In a further aspect thereof, the first encoder may receive red (“R”), green (“G”), blue (“B”), horizontal synchronization (“HSYNC”) and vertical synchronization (“VSYNC”) video signals from the computing system, combine the R and HSYNC video signals into a combined signal for transmission to the first decoder, combine the B and VSYNC video signals into another combined signal for transmission to the first decoder and combine the G video signal and the non-video signal into the last combined signal for transmission to the first decoder.
In still another embodiment, the present invention is of a computer network comprised of a plurality of nodes, each having a DTE device coupled thereto, and a connective structure arranged, for example, in a bus topology, which interconnects the plural DTE devices into a computer network. The DTE device coupled to at least one, and preferably, plural ones, of the nodes, further comprises a computing system located at a first location, preferably common to the plural computing systems, for example, a shared computer room or a common support structure such as a rack, a human interface located at a second location, each remotely located relative to the first location and preferably remotely located relative to the other second locations, a first interface device coupled to the computing system, a second interface device coupled to a monitor and an I/O device of the human interface and a 4-wire cable coupling the first and second interface devices. An encoding circuit of the first interface device receives, from the computing system, plural video signals to be transmitted to the video monitor and a non-video output signal to be transmitted to the I/O device. The encoding circuit combines the non-video signal with a selected one of the plural video signals to produce a combined signal and transmits the combined signal over a selected pair of the transmission lines of the 4-wire cable. A decoding circuit of the second interface device receives the combined signal from the first interface device and separates the combined signal into the video signal to be transmitted to the video monitor and the non-video signal to be transmitted to the I/O device.
In one aspect thereof, an encoding circuit of the second interface device receives a non-video input signal from the I/O device and encodes the received signal for output onto a selected pair of the transmission lines for transfer to the first interface device. In another aspect thereof, a decoding circuit of the first interface device receives the non-video I/O input signal from the selected pair of transmission lines and decodes the non-video input signal for transmission to the computing system.