ML20008D458

Applicant Exhibit A-88,consisting of Excerpt of Document from Unidentified Author Re Channel Loading Stds in General

ML20008D458
Person / Time
Site:	Seabrook
Issue date:	06/16/1989
From:	AFFILIATION NOT ASSIGNED
To:
References
OL-A-088, OL-A-88, NUDOCS 9003020271
Download: ML20008D458 (3)

Text

_-

'c.

'N k/G '79 Jo-W 3/#/-E Sm urn 2 mcle: )s co-channel statior.s rnultiphed. the problern of dete rmingggch systemsQ s r.ou;c ce tar.en into consicertiton m occicmg wnether a gwp cntnnelthe- was pre s -

fully occupied or not rapidly becomes an impossible one, n least n t

ent stage of development cf our irequency managergt go With E3. Acccrdingly, we plan to use the 15 r.nd 25 mile radii specifier. tion.

this decided it'is nece.s sary to acjust mileage s epygsops3ggventiontl staticns to account for the protected areat.. The rdlQ0MGMC Mtf&kte of urb &n-c onventient! rystems, as signm:.nts on occupied co-ch&r@MYequencie s will-not bc made unicer. the propos,ed site of the new fEcility it it lekr E 5 mile s f rom the pe cg raphic center of the U rbaniced Area involved. As te suburban-conventional rystems, tssignments on occupied co channel pairs will not be-u made unless the f:ite of the proposed station is at least 70 miles from the first suburban co-channel station authoriced and this is to be the rule regardles s of whethe r the channel :.s signed to that station is fully occupied er net, n/

Channel Loading Standards j 1

In General l

64. For channel loading, in the absence of e.ctual experience and data, es-pecitlly for trunked rystems of radio communication of the type we have under consideration at 0 0015.c, we felt we should rely on the number of mobile l units in operation as a base from which to set up channel occupancy figures. l We have used mobile units, for, over the years, in the Ir.nd mobile services, 1 we have developed a series of guides for determining the channel requirements ' 1 of licensees in the several services. i j

85. For example, in the Police Radic Service, we have found that, as a gen-e:cl rule, a channel pair can be employed in an effective manner in dispatch- l ing 50 mobile units of the vehicular type and an even greater number of port- '

able or-hand carried units.- In this we . recognize that there are no two situa-tions exactly alike and that there are many factors to be taken into account.

Among them are average message length; the number of units in operation in  !

any given time per2od; the number of times, each hour, the dispatchert r.nd mobiles originate calls; the. number of dispatchers on duty at any one time; .

the size of the system (the number of communicatien channels available for use l

at r.ny one point in time); and, certainly, the nature of the functions and activi- l ties of the licensee. All of these factors have an impact on system capacity. l Nevertheless, as an overall cr average measure, we have determined that in  !

e 3_1,/ In any case in which the proposed transmitter site is within the 15 and 25 mile radii, such application, of course, will be studied with co-channel stations in the protected areas, until such time as the channel is loaded in accordance with applicable standards. We would note, however, that all of these procedures are subject to further study and review, and -:

based on day-to-day operating data, we may find they can be improved.

Should this be so, appropriate steps will be taken to reflect this experi-ence.

9003020271 890616 2 0 .,r R :,, d P a ge lo,s PDR ADOCK 05000443 o PDR

& fr$

~~

E o 3

y. x U

t 4 RR H CMES l i

'the Police Radio Service, 50 vehicular mobile units por channel is t retson- (

able t.nd realistic criter.on to apply in licensing stations in thr.t service. ,

1 There, the fre- -i l

- 86. This may be contraeted to the Business Radio Service.d were inten i

. quencies allocatewere designated to serve t. much broader group of eligibles t.nd the '

inherent differences in the nature of the communications of businessme

' of police departments.with each frecuency or cht.nnellicensed to serve apprcximately 90 m In densely populated r.rcas, whert the demand for business frecuencies J turned out to be very great and message loads correspondingly heavy, this-

' norm did not always provide licensees with the communication capacilities l Nonetheless, overall, the 90 mobile criterion proved they felt they needed.

to be a good guide in licensing str.tions in the Business Service.

Similar conclusions have been arrive'd at as to frequency Icading in the

< 8 7.

other services.

To illustrate, in the Taxicab Radio' Service, we know that a frequency pair can be employed effectively in dispatching 150 mobiles or Fur-more; and we have set channel loading in that service at a higher level.

ther, the communication needs and requirements of b:ensees in the Power and Petroleum Radio Services are not the same as those in other radio s This is in part due to the fact that radio facilities are used in different

- ice s. But waye and for different purposes by licensees in the several se that mobile units can serve e.s a good guide for frequency assignment purposes.

88. There is an added factor cf some significance. Where a channelis as-circuit discipline cf a i signed for the exclusive use of a particular licensee,It is relatively easy to do so, for the e high order can be maintained.ees using the system are under the direct cont an interest in seeing to it that his messages to and from his mobile units are not delayed. Also, system monitoring can be performed in a more efficient K

manner, licens een.

since station operators do not have to listen for the sig With these considerations message interruptions which cause inefficiencies.in In doingmind, this, we have service to a single entity and those serving several licensees.

we have designated categories for single licensees; for 2 to 5 licensees; and for over 5 licensees. J2/

89. Summari:ing, then, on the basis of the foregoing considerations and also from what we have learned from the vast record in this proceeding, we h1ve developed the norms or general rules to assist We used us in dete capacity to serve in an effective way the requirements of the u 32,/ See $89.802 of the new rules which deals with loading requirements f conventional systems.

no.o., 27-21 ( 5 /22 / 7 4)

Par

• 104