1、. -_ . W 3515789 0238579 790 W - 4-33- 37 i VOICE/DATA TM 5-811-9 TECH NI CAL MAN UA1 TELEPHONE SYSTEMS HEADQUARTERS, DEPARTMENT OF THE ARMY APRIL 1989 t Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-m 3535789 0238580 402 m TM 5-81 1-9 REP ROD UCTI
2、ON AUTHO RIZATION/RESTRICTIONS This manual has been prepared by or for the Government and is public property and not subject to copyright. Reprints or republications of this manual should include a credit substantially as follows: Department of the Army Technical Manual 5-811-9 VOTCEVDATA TELEPHONE
3、SYSTEMS By Order of the Secretary of the Army: CARL E. VUONO General, United States Army Chief of Staff - Official: WILLIAM J. MEEHAN II Brigadier General, United States Army The Adjutant General Distribution: To be distributed in accordance with DA Form 12-34B, requirements for Electrical Design In
4、terior Electrical System. I I The proponent agency of this publication is the Office of the Chief of Engineers, United States Army. Users are invited to send comments and suggested improvements on DA Form 2028 (Recommended Changes to Publications and Blank Forms) direct to HQUSACE, CEEC-EE, WASH, D.
5、C. 20314-1000. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Technical Manual NO . 5-811-9 3515789 0218581 349 TM 5-81 1-9 HEADQUARTERS Department of the Army Washington. DC 18April 1989 Chapter 1 . VOICWDATA TELEPHONE SYSTEMS Paragraph GENERAL pur
6、pose 1-1 scope . 1-2 Design process 1-3 References and list of terms 1-4 Chapter 2 DESIGN CONSIDERATIONS purpose . 2-1 Existing systems, facilities and conditions . 2-2 Switching system interface . 2-3 New system requirements . 2-4 Outside plant considerations . 2-5 Analysis of distributed switching
7、 2-6 Chapter 3 . INSIDE PLANT Chapter 4 . General 3-1 Switching equipment 3-2 System features . 3-3 Switch interface . 3-4 Nonswitching equipment 3-5 Environmental and facility requirements 3-6 Tamer systems . 3-7 Fiber optic terminal equipment . 3-8 OUTSIDE PLANT Purpose 4-1 General 4-2 Route selec
8、tion 4-3 Cable sizing -4-4 Aerial cable plant 4-5 Underground systems 4-6 Buried cable plant . 4-7 Loading 4-8 Attenuation 4-9 Fiber optic cable 4-10 Chapter 5 . GROUNDING Grounding of inside plant . 5-1 Grounding of oufside plant . 5-2 Page 1-1 1-1 1-1 1-2 2-1 2-1 2-1 2-1 2-1 2-2 3-1 3-1 3-1 3-4 3-
9、9 3-12 3-13 3-13 4-1 4-1 4-1 4-1 4-2 4-4 4-6 4-6 4-6 4-6 5-1 5-2 Appendix A . References Glossary Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Figure 1-1 3-1 3-2 3-3 3-4 3-5 4- 1 4-2 4-3 4-4 5-1 Table 3-1 3 -2 4-1 4-2 4-3 5-1 = 3535789 0238582 285
10、 TM 5-81 1-9 List of Figures Communication symbols Typical telephone instruments PBX system cabling Inside distribution with tip splice frame Inside distribution with floor vault PBX house and station cabling Storm loading map Cable sag chart Typical manhole configurations Typical underground rackin
11、g in manholes Single point grounding List of Tables Trunk sizing requirements Trunk medium selection guide Cable sizing for 5 percent growth Aerial cable weights in pounds per foot plastic sheathed w- BKTA-1 1-100 I Il00 PRI H88 1-100 100-662 COILS USH OR PULL BRACE, SHOIYING HEIGHT AND CLASS AND TH
12、E YEAR OF THE 3RACE POLE 0 169 O IXISTING POLE POLE NUMBER, LENGTH, 9ND CLASS MAY BE SHOWN AS APPLICABLE IROPOSED POLE NUMBER, LENGTH, AND LASS SHOWN :XISTING POLE TO BE MOVED 5. AS SHOWN :XISTING POLE TO BE REMOVED IUUBER, LENGTH, AND CLASS SHOWN XISTING 30 FOOT CLASS 5 POLE, TO BE EPLACED WITH A 3
13、5 FOOT CLASS 5 POLE Figure 1-1. Xommunication symbols continued. ? -2 . , 41174 0 0 MH1028 TYPE A 12x 5x 6-6“ o EXPLANATION UNDERGROUND CONDUITS AND MANHOLES, SHOHING MANHOLE NUI.IBERS AND THE WALL TO WALL (UN) DISTANCE BETIMEN THEM FOUR MULTIPLE CLAY DUCTS ARE SHOW 100-PAIR LOADING COIL CASE EQUIPP
14、ED WITH (E/*) 100 H-88 COILS, PAIRS 1-100 LOADED POLE UNE SHOWNG CENTER-TO-CENTER SPAN DISTANCE EXISTING htANHOLE, WITH COVER VISIBLE MANHOLE (MH), HANDHOLE (HH). OR PULL BOX (P), SHOhING ASSIGNED NUMBER PROPOSED MANHOLE THE DIMENSIONS ARE SHOWN AS LENGTH x WIDTH x HEADROOU AND ARE THE INSIDE MEASUR
15、EMENTS TYPE OF MANHOLE I5 ALSO SHOW4 Figure 1-1. -Communication symbols continued. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-a a a 3515789 0218585 T94 = CHAPTER 2 D ES I G N CO NSI D ERATI O NS TM 5-81 1-9 2-1. Purpose. Before beginning the det
16、ailed designproc- ess, two fundamental questions or issues should be addressed in order to establish the basic approach for the new system, and essentially serve as the foundation for the entire project. Normally it will benecess? to analyze anumber of different design alternatives from an economic,
17、 maintenance, perform- ance and appearance perspective. These issues include: a. Outside plant. The use of direct buried cable, under- ground conduit and cable, and aerial cable. b. Switching equipment. The use of distributed or centralized switching. 2-2. Existing systems, facilities, and condition
18、s. Before the various design approaches can be properly ad- dressed, a clear understanding must be established of the existing network, equipment, cable facilities and capabilities of the network, with which the new system will interface. Also, the general environment and conditions in which the new
19、 system will be constructed and operated must be consid- ered. 2-3. Switching system interface. For access to the public switched network the switching equipment portion of the system will interface with either the postDCO or the local telephonecompany. Each situation requires adifferent design appr
20、oach and different considerations. If the switching equip- ment is to interface with a post DCO, the potential use of a remote switch should be investigated. In addition, the type of trunks which are to be interfaced must be identified. 2-4. New system requirements. Ideally the require- ments should
21、 be clearly defined during the planning process and provided in sufficient detail to allow performance of the design analysis andidentification of the best overall approach. However, before proceeding, a quick review should be per- formed to insure that these telecommunication requirements are clear
22、ly defined. Some of the major issues which some- times cause misunderstanding are briefly covered in this chapter; hopefully if they are used as a checklist, unnecessary confusion can be avoided. a. Voice circiiits. Voice circuits are often referred to as both trunks and lines, which can cause some
23、confusion espe- cially if the user is only familiar with key type systems. In general, lines are used to connect people to equipment and trunks are used to connect equipment to equipment. Where practical, the designer should attempt to stay with this conven- tion. Almost everything included in the d
24、esign is a function of lines required therefore, it is imperative that this parameter be accurately defined. If not otherwise provided, the follow- ing criteria can be used as a general guide. The figures are based upon the square footage of the building and the type of administrative functions perf
25、ormed. It is stressedthat they do not include data requirements nor is the guide applicable to nonadministrative functions. Area Usage Executive Technical Secretarial Clerical LinesII000 sqj 8 to 12 7 to 10 6 to 8 5 to7 To accurately design the system in a new facility the designer should contact th
26、e prime ArchitectEngineer to obtain floor plans and then discuss the functions with the administrative staff of the facility. 6. Data circuits. Many organizations are using telephone lines to transmit data. While todays PBXs are designed to accommodate this requirement, it is not normally advisable
27、to route permanent point-to-point data circuits through the PBX as this can degrade the performance of the system. An exception to this is when the switch is to be used to facilitate modempling, protocol conversion, or serve as an integral part of thedatanetwork. While theuseof adigital PBXallows da
28、ta circuits to be switched, just as voice circuits, a non- blocking PBX should be considered if data transmission demands are expected to be significant. To eliminate the chance of blocking, a non-blocking PBX provides unique paths for ali line and trunk circuits thereby preventing the possibility o
29、f a line being denied access to another available line or trunk. In general, if a data connection is to be of a constant nature, it should be excluded from the design. However, if the requirement is to be intermittent or switched, it should be clearly identified and included. 2-5. Outside plant cons
30、iderations. With many designs, outside plant considerations will be minimal as the objective is to design a PBX and the associated inside plant; however, if thenew systemrequires outside plant or modifications to the existing outside plant, aplan must bedevelopeddetailing how direct buried, undergro
31、und or aerial cable will be used. Many systems will incorporate the use of all of these construction techniques; however, normally one method will predominate. Each method has advantages and disadvantages and is par- ticularly suited for specific applications. a. Underground cable. If space in ducts
32、 is available in an existing conduit/manhole system, underground cable in con- duit is the preferred approach. This method is usually more economical and less disruptive to the surrounding environ- ment than other methods of cable placement. Additionally, major routes that are likely to experience f
33、requent change or growth are likely candidates for underground conduit. Cables in the immediate vicinity of the post central office are often placed in underground conduit and manhole systems to sim- plify access for maintenance andexpansion. However, if duct space in an existing conduiVmanhole syst
34、em is not available, implementation of a new conduiVmanhole system should be specified only if there is a definite need or requirement that cannot be satisfied with direct buried cable or aerial cable, The reason for this approach is the significant cost of con- 2-1 Provided by IHSNot for ResaleNo r
35、eproduction or networking permitted without license from IHS-,-,-3535789 0238586 920 TM 5-81 1-9 struction of a new conduit/manhole system. Also, with the high initial construction cost these systems should always be sized to accommodate a growth of at least 100 percent. b. Direct buried cable. In m
36、ost situations, if under- ground cable is not applicable, direct buried cable will be the preferred approach. Although direct buried cable would not be as secure as underground cable, it is less susceptible to environmental damage from forces such as lightning, re- quires less maintenance, is usuall
37、y more economical to construct, andis more pleasing aesthetically than aerial cable. It is especially useful for routes which are not likely to require frequent expansion or replacement. The major disadvantages of direct buried cable plant are: The cable is exposed to damage from rocks and debris du
38、ring construction. However, with proper construction techniques this should not present problems. The cable may experience possible future damage result- ing from below ground construction along the cable route. Expansion or replacement is difficult. However, the effectof this limitationcan bemitiga
39、ted with theproperaccess points such as pedestals, cross connect boxes, and handholes. c. Aerial plant. In some situations where aerial plant is already in use or electric pole lines are available, the use of aerial plant should be investigated to determine if it is eco- nomically advisable. However
40、, it should be remembered that aerial plant may be more expensive even with existing pole lines. This is due to the need to change out poles for load handling requirements and relocating existing utilities to provide the necessary road clearance and satisfy the electrical clearance requirements of t
41、he NFPA 70 and ANSI C2. Aerial plant is sometimes useful in areas that have difficult soil conditions (rocky or marshy) and when installing cable in rough or hilly terrain. In addition, it can be very helpful when installing cable in areas that are already congested with underground utilities. In ge
42、neral it should be realized that the design of aerial plant pole lines is a rather complicated art, especially when the various NFPA 70 and ANSI C2 require- ments and vehicular traffic requirements are considered; therefore, aerial plant should only be used if there is a specific need that cannot be
43、 satisfied with underground or direct buried cable. 2-6. Analysis of distributed switching. With the decreasing cost of computing power in relation to the cost of installed cable, it is often economically advisable to utilize a small remote switch (or a number of remote switches) as 2-2 opposed to a
44、 single large centralized switch. This concept is referred to as distributed orremote switching. Normally, it is used in conjunction with a host switch, which performs much of the initial call processing and houses the user data base. The remote switch can be connected to the host via physical coppe
45、r circuits, T-carrier, or a fiber optic system. In Department of Defense OD) networks, fiber optic systems should be the predominate choice to link the remote and host switch. Typically the distributed switching concept is only applicable in larger networks that encompass arelatively wide area. It i
46、s also likely to be more beneficial if the users tend to be concentrated in nodes. Economically the concept is cost effective by reducing the amount of cable that must be installedoverrelatively long distances. It also can increase the quality of signal transmission (data and voice) as the signals a
47、re transmitted digitally between the host and remote switch and the analog station loops are much shorter. However, the initial equipment costs of a remote switch/host switch ar- rangement is almost always more expensive than a single large central switch with the same number of lines. The remote sw
48、itch is only beneficial when the decreased cable costs offsets the additional cost of a distributed switching system. Remote switches also offer the advantage of easier accommodation of growth and, in some cases, additional system redundancy. Utilization of T-carrier or fiber optics to perform uunki
49、ng between the host and remote switches al- lows additional capacity to be added at a later date. Also, many remote switches can continue to process calls within their respective nodes after the host switch becomes inopera- tive. In addition, some remote switches can be equipped with alternate trunks to the outside world. With this capability the remote switch can be used to contact the outside world even if the trunks to the host switch are severedor become inopera- tive. In
