Analog Signals. Introduction

Transcription

1 Section 1: Metallic Media Chapter 1: Principles of Transmission Analog Signals Introduction Sinusoidal Signals A review of some of the fundamental concepts of voice telephony is covered in this section. It serves as an introduction to the subject of analog signals. Subsequent sections provide a concise and in-depth treatment of both analog and digital transmission. An analog signal is in the form of a wave that uses continuous variations in time (e.g., voltage amplitude or frequency variations) to transmit information. The most fundamental example of an analog signal is a sinusoid. An example of a sinusoid is shown in Figure 1.4. Figure 1.4 Example 1 of a sinusoidal signal A 0 T t T A = Amplitude 0 = Zero t = Time T = Time for one cycle 2006 BICSI 1-19 TDMM, 11th edition Corrected April 2007

2 Chapter 1: Principles of Transmission Section 1: Metallic Media Sinusoidal Signals, continued A sinusoid is an oscillating, periodic signal that is completely described by three parameters: Amplitude Frequency Phase In Figure 1.4, the amplitude of the sinusoid is A. The sinusoid oscillates with a period indicated by the interval T, called the cycle time. The number of these periods that occur in a second defines the frequency (f) of the sinusoid in cycles per second (Hz). Cycle time and frequency are related by the relationship f = 1/T. For example, a sinusoid with a cycle time of.001 seconds (sec) has a frequency of 1000 Hz. Hertz (Hz) is the standard unit of frequency measurement. The range of frequencies that human beings can hear is approximately 20 Hz to 20,000 Hz. Voice telephone circuits are generally limited to the range of 300 to 3400 Hz, which provides adequate quality for normal conversation. Standard notations for frequencies often encountered in communications systems are shown in Table 1.7. Table 1.7 Common units of frequency measurement Unit Abbreviation Value Kilohertz khz 1000 Hz Megahertz MHz 1,000,000 Hz (1000 khz) Gigahertz GHz 1,000,000,000 Hz (1000 MHz) TDMM, 11th edition BICSI

3 Chapter 2: Electromagnetic Compatibility Considerations for Electromagnetic Compatibility (EMC) in Cabling Systems General Guidelines Against Electromagnetic Interference (EMI) General Guidelines for Electromagnetic Compatibility (EMC) Electromagnetic Interference (EMI) Filters Data Line Filtering Electromagnetic Compatibility (EMC) by Filtering External Magnetics Interference Reduction in Shielded Rooms Electromagnetic Interference (EMI) and Bandwidth of Balanced Twisted-Pair Cabling Unwanted Signal Coupling Mechanism Balance of Twisted-Pair Cabling Shield Effectiveness and Ground Loop Unwanted Signal Summary BICSI 2-iii TDMM, 11th edition Corrected April 2007

4 Chapter 2: Electromagnetic Compatibility Figures Figure 2.1 Three electrostatic discharge modes Figure 2.2 Common mode versus differential mode Figure 2.3 Typical electromagnetic interference filter Figure 2.4 Field-to-cable and ground loop Figure 2.5 Balance Figure 2.6 Cabling shielding and grounding Figure 2.7 Ground loop unwanted signal Tables Table 2.1 Factors that can affect electromagnetic interference in nonrobust telecommunications equipment Table 2.2 Factors that can affect electromagnetic interference in nonrobust sites..2-9 Table 2.3 Four levels of immunity Table 2.4 Severity levels for open circuit voltage TDMM, 11th edition 2-iv 2006 BICSI

5 Chapter 2: Electromagnetic Compatibility Electromagnetic Compatibility (EMC) by Filtering, continued External Magnetics Filtering of a system s cabling and other signal conductors is generally accomplished by external magnetics that block CM signals from entering the equipment (e.g., CM chokes). Magnetic materials significantly increase the inductance with minimal looping of associated conductors and cables. Magnetic Beads Magnetic beads are often used for filtering. More than one bead may be required. Large Magnetic Toroidal Structures Fairly large magnetic toroidal structures may be used in a manner similar to a bead for filtering cables by fitting the structure around the entire cable. Interference Reduction in Shielded Rooms For many locations, a reduction in the electrical power of the interfering signals by as little as 10 times can make a dramatic difference in the performance of the telecommunications system in the room. These reduction levels are routinely accomplished by careful applications of shielding materials or by the use of a prefabricated shielded room BICSI 2-31 TDMM, 11th edition Corrected April 2007

6 Chapter 2: Electromagnetic Compatibility Electromagnetic Interference (EMI) and Bandwidth of Balanced Twisted-Pair Cabling Applications on high-speed local area networks (LANs) are making greater bandwidth demands on balanced twisted-pair cabling systems. Several years ago, the debate was concerned with 100 Mb/s applications today Gigabit Ethernet (1000 Mb/s) LAN applications are commonplace. Cable manufacturers have made tremendous gains in the performance of balanced twistedpair cables and equipment designers are evaluating more efficient ways of encoding and transmitting information, which enhances the bit-rate capacity of such cables. However, there continues to be some EMR and some susceptibility to EMI. Unwanted Signal Coupling Mechanism Three elements are necessary to produce an EMI problem. There must be a(n): Unwanted signal source. Receiver circuit that is susceptible to unwanted signal. Channel for the unwanted signal to be coupled from the source to the receiver. Figure 2.4 shows two mechanisms for unwanted signal coupling into the receiver; namely, induced unwanted signal due to external EM field coupling and conducted unwanted signal due to external ground loops. Both are equally important. The induced CM coupling voltage (voltage common mode [V cm ]) is a function of the electric field strength (E) and the loop area formed by a conductor of length (l) that is suspended at an average height (h) above the ground plane. TDMM, 11th edition BICSI

7 Chapter 3: Work Areas Balanced Twisted-Pair Telecommunications Outlet/Connector, continued Figure 3.1 Pin/pair assignments The T568A pin/pair assignment is preferred, and optionally, the T568B pin/pair assignment may be used if necessary to accommodate certain eight-pin cabling systems. These illustrations depict the front view of the telecommunications outlet/connector. The colors shown are associated with the horizontal distribution cable. Pair 2 Pair 3 Pair 3 Pair 1 Pair 4 Pair 2 Pair 1 Pair White Green Green White 3 4 White Blue Orange White 5 6 White Blue Orange White 7 White Brown 8 Brown White White Orange White Blue Orange White Green White 5 6 White Blue Green White 7 White Brown 8 Brown White Jack positions Jack positions T568A T568B NOTE: Telecommunications outlet/connectors of a given category/class shall meet the corresponding performance requirements provided in Table 4.15 in Chapter 4: Horizontal Distribution Systems BICSI 3-3 TDMM, 11th edition

8 Chapter 3: Work Areas Optical Fiber Telecommunications Outlet/Connector Optical fiber cables are terminated to optical fiber telecommunications outlet/connectors in the work area. These optical fiber telecommunications outlet/connectors are required to comply with appropriate requirements found in documents published by the American National Standards Institute (ANSI), International Organization for Standardization/International Electrotechnical Commission (ISO/IEC), and other standards organizations. There are many optical fiber connector/adapter types that satisfy the mechanical and transmission performance specifications of cabling standards. The telecommunications distribution designer may consider any of these optical fiber connector/adapters. Telecommunications Outlet Box Considerations The following guidelines for planning the location of telecommunications outlet boxes in the work area should be considered: Each occupant work area must have a minimum of one telecommunications outlet box location. For work areas in which it may be difficult to install future additional telecommunications outlet/connectors (e.g., in private offices), a minimum of two telecommunications outlet box locations should be provided and located for equipment access flexibility (e.g., on opposing walls). Work area telecommunications outlet box size requirements vary based on codes, standards, and local customs, as follows: The outlet box should be a minimum of 101 mm (4 in) x 101 mm (4 in) x 57 mm (2-1/4 in). This will accommodate one or two 27 mm (1 trade size) conduits. Where a larger conduit is required, the box size should be increased accordingly. A maximum 35 mm (1-1/4 trade size) conduit will require a 120 mm (4-11/16 in) x 64 mm (2.5 in) outlet box. Specialty boxes may be used in place of the above as appropriate. Telecommunications outlet boxes may require supports for attaching the box and a suitable faceplate to support the telecommunications outlet/connectors that are housed by the work area telecommunications outlet box. TDMM, 11th edition BICSI Corrected April 2007

9 Section 1: Horizontal Pathway Systems Chapter 4: Horizontal Distribution Systems Cable Tray Dimensions, continued Table 4.12 Cable trays (common types) Ventilated Ventilated Solid Basket Ladder Trough Channel Bottom Tray Lengths 3.7 m (12 ft) 3.7 m (12 ft) 3.7 m (12 ft) 3.7 m (12 ft) 3 m (10 ft) 7.3 m (24 ft) 7.3 m (24 ft) 7.3 m (24 ft) 7.3 m (24 ft) Widths 152 mm (6 in) 152 mm (6 in) 76 mm (3 in) 152 mm (6 in) 51 mm (2 in) (Inside) 305 mm (12 in) 305 mm (12 in) 101 mm (4 in) 305 mm (12 in) 101 mm (4 in) 457 mm (18 in) 457 mm (18 in) 152 mm (6 in) 457 mm (18 in) 152 mm (6 in) 610 mm (24 in) 610 mm (24 in) 610 mm (24 in) 203 mm (8 in) 762 mm (30 in) 762 mm (30 in) 762 mm (30 in) 305 mm (12 in) 914 mm (36 in) 914 mm (36 in) 914 mm (36 in) 406 mm (16 in) 457 mm (18 in) 508 mm (20 in) 610 mm (24 in) NOTE: The side rail outside depths (height) can be as much as 32 mm (1-1/4 in) more than the inside loading depth for ladder, ventilated trough, and solid bottom cable trays. Depths 76 mm (3 in) 76 mm (3 in) 32 mm (1-1/4 in) 76 mm (3 in) 38 mm (1-1/2 in) 101 mm (4 in) 101 mm (4 in) 45 mm (1-3/4 in) 101 mm (4 in) 51 mm (2 in) 127 mm (5 in) 127 mm (5 in) 127 mm (5 in) 101 mm (4 in) 152 mm (6 in) 152 mm (6 in) 152 mm (6 in) 152 mm (6 in) Rung 152 mm (6 in) spacing 229 mm (9 in) 305 mm (12 in) 457 mm (18 in) Radii 305 mm (12 in) 305 mm (12 in) 305 mm (12 in) 305 mm (12 in) 610 mm (24 in) 610 mm (24 in) 610 mm (24 in) 610 mm (24 in) 914 mm (36 in) 914 mm (36 in) 914 mm (36 in) 914 mm (36 in) Degrees of arc Transverse 101 mm (4 in) element spacing 2006 BICSI 4-45 TDMM, 11th edition

10 Chapter 4: Horizontal Distribution Systems Section 1: Horizontal Pathway Systems Capacity of Cable Trays The working load capacity of a cable tray system is determined by both the: Static load capacity of the tray, and The length of the support spans. NOTE: Total cable weight per meter (equivalent in feet) is rarely the limiting factor in determining the allowable cable tray fills for telecommunications cables. For horizontal cables, the allowable fill volume is usually obtained before the allowable weight per meter (equivalent in feet) is reached. Supporting Cable Trays Support cable trays should be supported by installing: Cantilever brackets. Trapeze supports. Individual rod suspension brackets. Support centers must be spaced according to the cable load and span, as specified for the cable tray s type and class by the manufacturer and applicable electrical codes. Supports should be placed so that connections between sections of the cable tray are between the support point and the quarter section of the span. Trays and wireways are usually supported on 1.52 m (5 ft) centers, unless they are designed for greater spans. A support must also be placed within 610 mm (24 in) on each side of any connection to a fitting. WARNING: Cable trays should never be used as walkways, ladders, or support for personnel. Cable trays must only be used as mechanical support for cables. Marking and Bonding Cable Trays All metallic cable trays must be grounded and all sections bonded in accordance with applicable codes, standards, and regulations. All cable trays and grounding conductors should be clearly marked in accordance with appropriate codes, standards, and regulations. TDMM, 11th edition BICSI Corrected April 2007

11 Section 2: Horizontal Cabling Systems Chapter 4: Horizontal Distribution Systems Horizontal Connecting Hardware General Connecting hardware for horizontal cabling includes: Telecommunications outlet/connectors. Connectors used in the horizontal cross-connects (HCs [floor distributors (FDs)]). Consolidation point (CP), horizontal connection point (HCP), and transition point (TP) connectors (optional). All connecting hardware used for horizontal cable connections must meet the requirements for reliability, safety, and transmission performance specified in the applicable codes, standards, and regulations. Equipment Connections at Horizontal Cross-Connect (HC) Floor Distributor (FD) Horizontal cables should not be connected directly to the telecommunications equipment. Instead, suitable connecting hardware and equipment cable should be used to make the connection. Patch panels and cross-connect blocks should be located so that the combined length of cables and cords used to connect equipment at the HC (FD) does not exceed 5 m (16 ft). Telecommunications Outlets/Connectors Cabling Adapters Telecommunications outlets/connectors should be mounted securely at work area locations. All horizontal cables that are not reserved for future use should be terminated with the standard telecommunications outlet/connector specified for that cable type. Telecommunications outlet/connectors should be located so the cord required to reach work area equipment is no more than 5 m (16 ft) long. Some networks and services require application-specific electrical components (e.g., impedance-matching devices) for equipment at the HC (FD), the work area, or both. These components, called cabling adapters, must not be installed as a part of the horizontal cabling. When required, cabling adapters must be placed outside the HC (FD) and telecommunications outlet/connector. This ensures that the cabling infrastructure retains its ability to accommodate a variety of services without modifications to the horizontal cabling. NOTE: Cabling adapters used in the work area, TR, or TE may have a detrimental effect on the transmission performance of the telecommunications cabling system. Therefore, it is important to consider each cabling adapter s compatibility with the horizontal cabling and the equipment to which it connects before attaching it to the telecommunications network BICSI 4-73 TDM Manual, 11th edition Corrected April 2007

12 Chapter 4: Horizontal Distribution Systems Section 2: Horizontal Cabling Systems 100-Ohm Balanced Twisted-Pair Cable Telecommunications Outlets/Connectors Each 4-pair 100 ohm balanced twisted-pair cable must be terminated in an eight-position connector at the work area. The telecommunications outlet/connector should be terminated directly to the horizontal cable with insulation displacement connectors (IDCs) and mounted on the telecommunications outlet/connector faceplate so that it is accessible for work area connections. All connectors that provide electrical connections between 100 ohm balanced twisted-pair cables must meet the appropriate requirements of local and national codes, standards, and regulations. Figure 4.15 shows a work area cable mated to one of two telecommunications outlets/ connectors mounted on a faceplate. Figure 4.15 Balanced twisted-pair work area cable Cable side Faceplate 8-Position telecommunications outlet/connector Modular plug User side TDM Manual, 11th edition BICSI

13 Section 1: Backbone Pathway Systems Chapter 5: Backbone Distribution Systems Sleeves or Slots, continued Figure 5.16 Typical sleeve and slot installations Cable strap Backbone cable 101 mm (4 in) 152 mm (6 in) Minimum 229 mm (9 in) Minimum 25 mm (1 in) Minimum curb mm (1 3 in) Floor slot Conduit sleeve through floor mm = Millimeter in = Inch Slot Quantity and Configuration Slots are typically located flush against the wall within a space, and should be designed at a depth (the dimension perpendicular to the wall) of mm (6 24 in), giving preference to narrower depths wherever possible. The location and configuration of the slot(s) shall be approved by a structural engineer. The size of the pathway using slots should be one slot sized at 0.46 m 2 (60 in 2 ) for up to 4000 m 2 (40,000 ft 2 ) of usable floor space served by that backbone system. The slot area should be increased by 0.46 m 2 (60 in 2 ) with each 4000 m 2 (40,000 ft 2 ) increase in usable floor space served by that backbone BICSI 5-29 TDMM, 11th edition Corrected April 2007

14 Chapter 5: Backbone Distribution Systems Section 1: Backbone Pathway Systems Open Shafts Open cable shafts are used when available and where large quantities of cables are required on a floor that is distant from the main ER (e.g., the main ER in the basement and a large quantity of circuits required on the 30th floor). Building managers normally direct cable shaft use requirements. Avoiding Elevator Shafts Do not locate backbone cable pathways in elevator shafts. Enclosed Metallic Raceways or Conduits Enclosed metallic raceways or conduits also are used as cable pathways. These raceways or conduits are: Sometimes used to run cables point-to-point (PTP) when intermediate splices or terminations are not required. Not effective for general distribution purposes but do provide a high degree of security and physical protection. Should be bonded and grounded to form a common bonding network (CBN). Conduit Fill for Backbone Cable Tables 5.6 and 5.7 show the conduit fill ratio guidelines for backbone cables; however, the number of cables that can be installed is actually limited by the allowed maximum pulling tensions of the cables. NOTE: This fill requirement does not apply to sleeves, header ducts, underfloor ducts, access floors, and conduit runs without bends and under 15 m (50 ft). TDMM, 11th edition BICSI

15 Chapter 7: Firestopping Firestopping and Disaster Avoidance, continued The information transport systems (ITS) installer must abide by the following articles in the NEC, 2005 edition: (D) (6). Supply Circuits and Interconnecting Cables Under Raised Floors. Abandoned cables shall be removed unless contained in metal raceways Definitions Abandoned Communications Cable. Installed communications cable that is not terminated at both ends at a connector or other equipment and not identified for future use with a tag Applications of Listed Communications Wires and Cables and Communications Raceways (A) Plenum...Abandoned cables shall not be permitted to remain Applications of Listed CATV Cables and CATV Raceways Plenums. Abandoned cables shall not be permitted to remain. Building construction plays a major role in compartmentation. Building codes require fire-rated walls and floors to: Isolate the areas in which hazards are likely to exist. Subdivide the areas to enhance the protection of lives and property. It is usually necessary to penetrate these fire barriers to add electrical and mechanical services into the areas in which they are needed. Even after a building is occupied, firewalls and floors may have to be penetrated as changes to building services are made. Revisions of telephone service and computer terminal connections are everyday events. Additional electrical power requirements, new plumbing, heating, ventilating, and air conditioning (HVAC) revisions, and security-alarm cabling all involve making holes in fire barriers. Generally, construction specifications require the trade penetrating the fire-resistive barrier to properly seal the opening to restore the integrity of the barrier. Unfortunately, when the person responsible for sealing the opening is unfamiliar with the requirements and unprepared for the task, the opening is often sealed improperly or is not sealed at all. Studies of notable fires have shown that such penetrations, when left open or improperly sealed, have played a dramatic role in the spread of fire, smoke, and toxic fumes. Today, a myriad of tested and qualified firestop systems can be used to restore the integrity of fire-rated walls and floors. Most building codes, regulations, and local ordinances require firestopping. According to NEC Article , Openings around electrical penetrations through fire-resistant-rated walls, partitions, floors, or ceilings shall be firestopped using approved methods to maintain the fire-resistance rating BICSI 7-5 TDMM, 11th edition Corrected April 2007

16 Chapter 7: Firestopping Firestopping Systems Introduction Preventing the passage of fire through a barrier penetration may depend on a single material that offers a complex balance of: Thermal resistance. Thermal conductivity. Appropriate Systems Adequate sealing at high temperatures. Controlled consumption. Durability to survive the: Turbulence of a fire. Rapid cooling and erosive impact of a hose stream. Many firestop systems combine several materials, each offering specific physical properties that contribute to the success of the overall design. Surviving the dynamics of a fire test depends on the interrelationship between: Component products and dimensions. Anchoring and installation techniques. A firestop seal system must provide an appropriate balance between: Durability. Ease of installation. Ease of maintenance. Some firestop seal systems can be installed from: Only one side when access to the other side of the barrier is impossible. The bottom of an opening because of the characteristics of the material. (This method may be used when the top of the opening is not accessible due to the equipment location.) Firestop seal repairs or reinstallations must be: Qualified by performance tests or engineered judgments. Simple to achieve. TDMM, 11th edition BICSI

17 Appendix A: Approved Methods of Firestopping Chapter 7: Firestopping Concrete Floor or Wall (Typical 25-Pair Cable) Figure 7.23 Concrete floor or wall (typical 25-pair cable) A A Section A-A NOTES: 1. Floor or wall assembly Minimum 114 mm (4-1/2 in) thick lightweight or normal weight concrete or nominal 203 mm (8 in) thick concrete block; maximum through-opening size is 51 mm (2 in) diameter 2. Penetrating item Cables: Maximum size 25-pair cables Cabling loading: Maximum 15 percent 3. Firestop putty Packed in through opening to a minimum of 114 mm (4-1/2 in). 4. A sleeve system projecting above the floor prevents down flooding. IMPORTANT: F rating = 3 hours T rating = 2 hours (0 hours with sleeve system) 2006 BICSI 7-57 TDMM, 11th edition

18 Chapter 7: Firestopping Appendix A: Approved Methods of Firestopping Drywall (Typical 50-Pair Cable [Maximum]) Figure 7.24 Drywall (typical 50-pair cable [maximum]) A 3 2 A Section A-A NOTES: 1. Wall assembly Fire-rated drywalls 2. Penetrating item 50-pair cables: 24 AWG [0.51 mm (0.020 in)] or smaller cable; maximum annular space between penetrating item and through opening 4.8 mm (3/16 in) 3. Firestop putty Minimum 38 mm (1-1/2 in) firmly packed into opening to fill the annular space between the cable and periphery of opening; an additional 3 mm (1/8 in) crown around the circumference of the cable IMPORTANT: F rating = 2 hours T rating = 2 hours TDMM, 11th edition BICSI Corrected April 2007

19 Appendix A: Approved Methods of Firestopping Chapter 7: Firestopping Concrete Wall (Typical 50-Pair Cable [Maximum]) Figure 7.25 Concrete wall (typical 50-pair cable [maximum]) A A Section A-A NOTES: 1. Wall assembly Minimum 127 mm (5 in) thick lightweight or normal-weight concrete or nominal 127 mm (5 in) thick concrete block 2. Penetrating item 50-pair cables: 24 AWG [0.51 mm (0.020 in)] or smaller cable; maximum annular space between penetrating item and through opening 4.8 mm (3/16 in). 3. Firestop putty Installed symmetrically on both sides of wall assembly to 38 mm (1-1/2 in) depth 4. Mineral wool or ceramic fiber Minimum 6 pound per cubic foot (lb/ft 2 ) density tightly packed to a depth of 51 mm (2 in) between putty. IMPORTANT: F rating = 2 hours T rating = 2 hours 2006 BICSI 7-59 TDMM, 11th edition Corrected April 2007

20 Chapter 7: Firestopping Appendix A: Approved Methods of Firestopping Concrete Wall or Floor (Metallic Pipes) Figure 7.26 Concrete wall or floor (metallic pipes) A A Section A-A NOTES: 1. Floor or wall assembly A minimum of 83 mm (3-1/4 in) thick lightweight or normal weight concrete; wall may also be constructed of concrete block; maximum size of opening 254 mm (10 in) by 762 mm (30 in) 2. Metallic pipe Maximum five pipes; the following types and sizes of pipe may be used: maximum 152 mm (6 in) diameter, schedule 10 or heavier steel pipe, 152 mm (6 in) diameter rigid metal conduit (RMC), 101 mm (4 in) diameter electrical metallic tubing (EMT), or 51 mm (2 in) diameter copper tubing or pipe; annular space minimum 19 mm (3/4 in). 3. Pipe insulation (optional) Maximum 25 mm (1 in) thick fiberglass or mineral wool pipe insulation; if fiberglass insulation is used, the F rating is 2 hours and the T rating is 1/2 hour, if mineral wool insulation is used, the F rating is 3 hours, and the T rating is 1-1/2 hour; if no insulation is used, the T rating is 0 hours 4. Firestop mortar Minimum 83 mm (3-1/4 in) depth for a 2- or 3-hour F rating or 178 mm (7 in) depth for a 4-hour F rating 5. Forming material (not shown) Plywood or polystyrene boards cut to close contour of opening; it should be removed after the mortar cures IMPORTANT: F rating = 2, 3, or 4 hours (See 3 and 4.) T rating = 0, 1/2, or 1-1/2 hours (See 3 and 4.) TDMM, 11th edition BICSI

21 Chapter 15: Building Automation Systems Foundation for Building Automation System (BAS) Integration, continued Cabling for voice and data systems is not always addressed during construction and is usually not a part of the construction budget. The traditional BAS relative to building management and life safety systems is usually planned as part of the electrical package and is, therefore, part of the budget and installed during construction. Planning and installation of the voice and data cabling is normally accomplished when the floor space is being prepared for occupancy. This means multiple cabling systems, pathways, and delivery methods are installed during various stages of the construction and occupancy. BAS products and technologies are typically upgraded every five to seven years. The latest BAS technology trends indicate a shift from the traditional system-specific cabling types to a more open system approach. As electronics and computer technology continue to evolve, the next generation of BAS controllers under development will tend to be smaller and serve dedicated functions. New intelligent endpoint devices will be developed and commonly implemented into the BAS applications (e.g., fire alarm devices will have processors; audio systems will use digital communications; access control [AC] will feature video feedback). These new technologies will provide a foundation for BAS devices to plug and play similar to today s computer and internetworking products. These technology trends will help to ensure future interoperability between different manufacturer s devices, controllers, and systems. With the emergence of multimedia applications and ever increasing broadband capabilities, the volume of shared information will increase, creating additional demand for BAS transmission speeds to also increase. Future BAS communications architecture will soon appear to be consistent with today s advanced local area network (LAN) communications architecture requiring high performance cabling systems. Today, it is possible to select the telecommunications cabling as the first system, instead of the systems equipment and active electronics, and incorporate the BAS into the telecommunications cabling distribution system. This allows the cabling investment for the building to correspond more closely to the building s desired lifecycle, rather than corresponding to any of the individual systems. A common misunderstanding is that telecommunications cabling refers only to the voice and data cabling (e.g., also referred to as LAN cabling). Telecommunications cabling is a concept, principle, or architecture developed to provide a standard scheme to any structure using cables or wires (e.g., electrical power distribution systems, music broadcasting, paging). The telecommunications cabling system designer should keep this principle in mind while designing such infrastructure. In fact, the term telecommunications as defined in the BICSI Information Transport Systems Dictionary states, Any transmission, emission, and reception of signs, signals, writings, images, and sounds; that is, information of any nature by cable, radio, optical, or other electromagnetic systems BICSI 15-3 TDMM, 11th edition

22 Chapter 15: Building Automation Systems Foundation for Building Automation System (BAS) Integration, continued If the voice and data cabling is installed with the BAS cabling during the construction phase, this: Allows one project team to engineer, install, and project manage the installation of all cabling. Can reduce the initial construction and ongoing operational costs. Can reduce installation labor hours by consolidating cabling and using a common pathway. Decreases the time required for overall project engineering. Minimizes damage to finished surfaces by installing all cabling during the construction. Creates a single cabling distribution system for easier administration and maintenance. Provides the customer with a single point of contact for integrating the cabling and pathways for all the systems. Reduces contention between trades. Makes construction and installation scheduling easier, improving the efficiency of the overall project. Provides flexibility for additions and rearrangements. Can improve response time to end user requests for cabling changes. Saves tenants money by reducing or eliminating the: Cost of installing voice and data cabling. Time required for moving in and setup. Rental costs by minimizing time for the cabling installation. Provides the building with a marketable advantage that could improve occupancy. If designed properly, is reusable for the life of the structure, when using open office cabling. TDMM, 11th edition BICSI Corrected April 2007

23 Chapter 17: Wireless Emerging Wireless Technologies and Related Standards This section explores some of the technologies that are emerging but have not been fully ratified by the standards bodies. P Working Group for Wireless Sensor Standards The P working group is defining the standard that will govern transducer electronic data sheets (TEDS). The standard will assist in integrating wireless technology for transducer connectivity. IEEE k Radio Resource Management IEEE k is a proposed standard for radio resource measurement. It will increase the manageability of WLANs by measuring radio and network information, which can be used by network management applications. IEEE n Enhancements for Higher Throughput IEEE n is the next step in WLAN standards. The a and g standards both deliver a maximum 54 Mb/s. The proposed n specification will use the same 5 gigahertz (GHz) frequency range as a but will raise the maximum throughput to 100 Mb/s or higher. This will improve the speed of wireless multimedia applications. IEEE Mobile Broadband Wireless Access (MBWA) IEEE addresses personal comouter (PC) technology in moving vehicles. The standard extends high-speed connectivity to vehicles traveling over 161 km (100 mi) per hour is a global standard, as it will support global connectivity in the same fashion as 3G cellular IEEE is an emerging standard that will specifically address wireless PC networks. Codes and Regulations In most countries, the telecommunications, electrical, and building industries are governed by codes and regulations so that the methods used to install equipment, electrical, and building elements are performed in a safe manner. Codes and regulations are important to these industries because they provide for life and property protection. Before an installation is begun, research is necessary to determine what codes and regulations are enforced within the jurisdiction where the work is being performed. NOTES: At the back of this chapter, see Appendix A: Major Wireless Standards Development Organizations, and Appendix B: Wireless Regulating Entities, for some of the entities that promulgate codes and regulations, and some of the codes and regulations that impact various elements of a wireless system design and installation. See Appendix A: Codes, Standards, and Regulations at the back of this manual for further information BICSI 17-7 TDMM, 11th edition

24 Chapter 17: Wireless Frequency and Wavelength General Description of Physics of Wave and Wave Theory Characteristics of Waves Radio waves, sound waves, and fluid waves share the same characteristics. Their sinusoidal components (see Figure 17.1) can be described by: Amplitude Amplitude is the size or magnitude of a voltage or current waveform. Frequency Frequency is a measure of the rate at which a periodic function repeats; it is the number of cycles or events per unit of time. Frequency can be further defined as the number of cycles occurring per second of an electromagnetic (EM) wave. Frequency is expressed in hertz (hz). Wavelength Wavelength is the distance between points of a corresponding phase of one complete cycle of a wave. Figure 17.1 Frequency, amplitude, and wavelength Wavelength Distance traveled in one cycle Amplitude Period = 0.5 second 0.5 second 1.0 second Frequency = Two cycles per second (2 Hz) TDMM, 11th edition BICSI Corrected April 2007

25 Chapter 19: Customer-Owned Outside Plant Direct-Buried and Underground Pathways, continued Shoring Requirements Requirements for Direct-Buried Methods In most locations, the AP will require right-of-way permits or easements before placing entrance facilities by direct-buried methods. Local policies and tariffs may specify charges for trenching and backfilling on private property when the AP (or their subcontractor) performs the work. BICSI recommends that any trench 1.52 m (5 ft) or more deep must: Be shored to prevent cave-in. Have a minimum clearance of 610 mm (24 in) from the edge of the excavated dirt pile to the nearest edge of the trench. NOTE: Always check with your local jurisdiction for possible additional requirements. Joint-Trench Required Separations When a joint-trench method is used, the following vertical or horizontal separations between telecommunications facilities and other facilities must be maintained. See Table Table 19.1 Vertical/horizontal separations Adjacent Structure Power or other foreign conduit Pipes (gas, oil, water) Street railways Minimum Separation 76 mm (3 in) of concrete, or 101 mm (4 in) of masonry, or 305 mm (12 in) of well-tamped earth. 152 mm (6 in) when crossing. 305 mm (12 in) when parallel. 1.0 m (3.3 ft) below top of rail. NOTES: Place cable in rigid PVC conduit for a distance of 3 m (10 ft) on either side of the pipeline crossing. If multiple pipelines exist, then extend conduit 3 m (10 ft) from the outside pipes. Place rigid steel conduit for a minimum distance of 7.6 m (25 ft) on either size of the center of the track (e.g., rails) crossing. If there are multiple tracks, the conduit should extend out 7.6 m (25 ft) on either side of the center of the outside tracks. For casings, the minimum is 4.6 m (15 ft) from top of rail BICSI 19-9 TDMM, 11th edition Corrected April 2007

26 Chapter 19: Customer-Owned Outside Plant Warning Tape Requirements To reduce the chance of an accidental dig-up, place plastic warning tape a minimum of 305 mm (12 in) below grade. Warning tape is either: Nondetectable (e.g., containing no metallic elements). Detectable (e.g., containing metallic tracings). Traditionally, nondetectable tape has been used since the cable sheath or copper itself provides detection. However, with optical fiber cable, detectable tape is recommended. The Common Ground Alliance (CGA) has adopted the color orange for telecommunications and community antenna television (CATV) cables. Coordinating Joint-Trenching Close coordination is necessary when joint-trenching. Figure 19.3 illustrates typical trenching dimensions. Figure 19.3 Typical joint trenching dimensions (section view through trench) 356 mm (14 in) minimum Note 1 Power cable Telecommunications cable 762 mm (30 in) minimum Note 2 Sand fill 305 mm (12 in) minimum 101 mm (4 in) minimum NOTES: 1. Excavation and backfill. 2. Fill to be clear of rocks and sharp objects. TDMM, 11th edition BICSI