KU-BAND DISTRIBUTION OF TELEVISION PROGRAMMING FOR THE CABLE INDUSTRY

PAUL A. HEIMBACH and GERALD S. KAPLAN

HOME BOX OFFICE, INC. and RCA AMERICAN COMMUNICATIONS, INC.

INTRODUCTION The success of Ku-band distribution requires the optimization of the Ku-band for satellite delivery of satellite system including satellite television programming has become performance, in orbit and ground accepted worldwide. Abroad, protection to insure continued European and Japanese satellite operation, and the frequency plan to systems are based on the Ku-band ensure maximum utilization of the frequency to take advantage of (1), orbital resouce. On the ground higher power signals, which result careful planning and operation of in a less costly ground segment, and the Ku-band receiving earth stations (2), relative freedom from RFI, is needed to insure superior quality which facilitates antenna siting. and reliable reception of the signal. In the United States, Ku-band has been selected for network television In July, 1986 subsidiaries of HBO program distribution and for the and RCA formed a joint venture establishment of nationwide called Crimson Satellite Associates satellite newsgathering services by to build, acquire, and launch a Ku­ several entities. It is also the band satellite called K3. Crimson preferred transmission technology also has the option to acquire and for VSAT networking to establish launch a second Ku-band satellite, private voice/data, transaction and called K4, and, subject to FCC video conferencing systems. approval, to co-locate it with K3. Launch of K3 is scheduled for Mid- By 1992 67 percent of the satellites 1989. world wide will be operating at Ku­ band. And of the 6 domestic U.S. An existing RCA Ku-band satellite, launches planned between now and Kl, serves to provide interim 1990, five are either Ku-band or capacity until 1989 and allows the hybrid. cable industry to build confidence in Ku-band distribution by providing The use of Ku-band for program a time to experiment and learn. distribution to CATV and SMATV Thereafter Kl will serve as an systems is an evolutionary process, integral component in the satellite not a revolutionary step. Ku-band system protection plan. distribution allows affiliates to serve subscribers considered WHY KU-BAND unreachable at C-band, eliminates the problems of C-band terrestrial The use of Ku-band for program interference encountered at some distribution to CATV and SMATV primary receive locations, provides systems is a natural step in our a 2nd totally redundant signal industry, as illustrated by distribution path thus protecting examining future satellite systems. against program disruption and, over the next 3 years, allows an A review of launch schedules reveals unprecedented increase in the that the next generation of efficient use of a satellite orbital satellites are predominately Ku slot and spectrum. satellites.

268-1987 NCTA Technical Papers Between now and 1992, 59 proposed In most cases, economical communications satellites are 1.8 meter Ku dishes for authorized for launch worldwide. Of rural cluster cable these, 52 will be Ku-band or Ku­ systems not yet receiving hybrids, six will be C-band and one satellite programming, (Italy's) will operate at another thereby providing new frequency. services to homes heretofore unreached by Between 1987 and 1990, Ariane has programmers. reservations or contracts to launch 32 communications satellites on 24 Ku earth stations costing rockets. Of these 32 satellites, approximately $1300 can be only one does not have a Ku-band used by operators to reach payloacr:- Thi~~scilpabl~_ _!?ct unpassed multi-family merits emphasis: Every units (SMATV) prior to an communications satellite launched urban cable build or in between now and 1990 will be K-band, lieu of long cable runs to save one. reach a rural pocket such as a trailer park or Ku-band has become the clear choice apartment complex. for future capacity for four important reasons: 2. Superior Protection Against Failure:------1. Business Benefits to the Cable Ku-band offers the opportunity Industry: to create a superior level of The benefits of Ku-band stem protection from catastrophe that largely from its regulatory is cost-effective, flexible, and heritage. C-band satellites are adaptable to the evolving secondary users of a shared­ business environment. The frequency assignment and objective is to maintain the consequently must not interfere business with minimal disruption with the terrestrial microwave to program continuity or the links also using the spectrum. installed receiving system. The interference is held to a minimum by operating C-band Protection at Ku-band makes satellites at low power levels. possible a protection Also, reception of C-band configuration ensuring minimum signals can be difficult or disruption of service by impossible because of eliminating the need to repaint interference from these same earth stations at a new terrestrial microwave links. satellite or disperse programming across several The Ku-band satellite service, satellites in the event of on the other hand, is a primary catastropic failure. user and does not need to protect any other radio service. Unlike any protection plan at Consequently, Ku satellites can C-band, Ku-band protection is be more powerful than those achieved by on-board redundancy, using C-band, permitting the use an in-orbit spare satellite and of smaller, less expensive a ground spare satellite. The equipment to receive the signal. growing base of Ku satellites This naturally provides business means the cost of protection is benefits to both programmers and reduced to each user while the cable affiliates, particularly number of C-band systems as they look to serve areas not decrease, the cost of protection yet passed by cable plant. will be shared by fewer users, These business benefits include: and thus cost to each user will increase. 0 The ability to situate a Ku earth station at an 3. Technical Evolution: urban headend regardless The-early~-band satellites of the presence of were primarily designed for the terrestrial microwave transmission of high volume signals, which will voice and data traffic from facilitate construction as point A to point B using the major urban markets relatively large antennas. Ku are cabled. satellites being constructed today and in the future will be

1987 NCTA Technical Papers-269 more sui ted to the predominant to 12.2 GHz band on the downlink. uses of satellite capacity Each satellite includes sixteen video and point-to-multipoint transponders with 47 watt TWTAs (60 small dish data transmission. watts with FCC approval). Eight of the transponders will be Ku-band satellite systems have horizontally polarized and eight been operational since 1980. will be vertically polarized. For The technology and performance high reliability, these sixteen characteristics have been transponders are protected by a studied and well-defined. The total of six spare TWTAs on board past 7 years of experience the satellite. allows this new generation of Ku-band satellite to overcome The transponders will be fully many of the problems experienced protected against eclipse outage. in the past. This lnsures full operation and power for 24 hours a day, 365 days a The early problems of degraded year for the 10 year design life of performance due to rain the satellite. attentuation exhibited in the first generation Ku satellites The high power available from the have been overcome through the TWTAs on board the satellite will be development of more powerful directed to the earth in one of satellites capable of providing three modes that are reconfigurable increased signal margin. Using on orbit by ground command. These the antenna sizes our industry modes will allow any individual employs, rain no longer degrades transponder to be configured as a service for any significant CONUS beam or an East beam or a West time. beam. This allows the entire transponder power to be concentrated 4. Channel Capacity: in the areas of the country where Only--24--channels of video the signal is desired. Selectable programming can be transmitted coverage ensures that each from each C-band orbital transponder has flexibility for the location. Therefore, headends user and can readily accomodate are now "antenna farms" with an varying traffic usage patterns. ever-increasing number of dishes looking at a variety of C-band An EIRP pattern showing the minimum satellites. The proposed EIRP valves for 60 watt transponders channelization plan of the expected for each of the transponder Crimson Satellite Associates modes is shown in Figures 1, 2, and Ku-band satellite system would 3. The East beam provides coverage allow each TVRO to receive a to the Eastern and Central time total of 32 program channels zones while the West beam covers the from a single orbital location. Pacific and Mountain time zones. The CONUS mode covers the 4 8 contigious states. Hawaii is CHARACTERISTICS OF THE K3 and K4 covered in the West beam and CONUS SATELLITES modes. Two video signals per transponder can be accommodated, The present FCC rules governing Ku­ allowing up to 32 television band satellites operating in the FSS channels to be distributed by one band allow more flexibility in satellite. satellite design: i.e. higher power densities are permitted (compared Another innovative feature of this with C-band) since interference with satellite is the on board dynamic terrestrial networks is not a limiter amplifiers (DLA). When the problem. DLA is operating in the limiter mode, the transponder output is The design of the K3 and K4 maintained at full downlink power satellites incorporate many advanced even when the uplink signal fades. features that will enable the high This insures that the overall video performance requirements of the CATV signal to noise ratio will be and SMATV industry to be met across affected minimally by uplink fades the country. and will obviate the necessity for expensive uplink power control at The Ku-band satellite system the transmit earth station. The operates in the 14.0 to 14.5 GHz inclusion of the DLA on board the band on the uplink and in the 11.7 satellite greatly enhances overall

270-1987 NCTA Technical Papers link robustness and provides a K3/K4 PROTECTION PLAN superior video signal in the event of propagation effects on the An earlier section (Why Ku-band) uplink. referred to the superior protection from catastrophe offered by a well The planned launch of K3 is in Mid- designed Ku-band satellite system. 1989. An additional satellite (K4) The proposed Kl, K3, K4 system can be launched at a later time and discussed here will provide a level co-located with K3 (subject to FCC of protection unheard of in other approval). The two satellites (each satellite systems. with sixteen active transponders) would then provide a total of 32 Satellite-protection requirements channels at a single orbital have grown along with our industry's location. The satellite design is revenue stream. In the early days such that each of these 32 channels of satellite distribution, utilizes the full power of its own protection involved relocating transponder. This is accomplished programming to other satellites in primarily by narrowing the bandwidth the event of failure. Later of each transponder from its nominal satellites enhanced reliability by 54 MHz to a nominal 27 MHz upon incorporating on-board spare parts. ground command. This frequency plan, which is depicted in Figure 4 Today, our industry uses dishes at accomplishes an extraordinarily more than 25,000 commercial efficient utilization of the orbital locations to receive satellite location. programming. The protection scheme for the 1990s must provide The satellite system design has been programmers with the ability to stay optimized for the transmission of in business in case of catastrophic television programs. The high power failure without repointin~ thousands TWT's (operating at Ku-band) provide of dishes overnight. increased margin against propagation effects thereby permitting a Components of a sound, cost substantial reduction in ground effective protection system include segment costs as well as a (1) on-board protection (spare substantial increase in the number components); (2) in-orbit of locations where an earth station restoration capability where the can be placed. The innovative satellites move, not the dishes; {3) frequency plan, employing ground spares. Such protection will transponders with switchable be achieved with the Kl, K3, K4 bandwidths, permits a single orbital satellite system. location to provide 32 full power television signals into a single Once K3 is operational, the Kl relatively inexpensive receive satellite will serve as an in-orbit antenna. This ability to spare, which can be rapidly reconfigure each transponder relocated to the K3 position in the individually and transmit the full event of a total K3 failure. transponder power in either full Consequently, service restoration CONUS, Eastern or Western modes, the occurs in space, obviating the need protection against the effects of to repaint thousands of dishes. uplink rain fade afforded by the DLA, the six spare TWT's and other Furthermore, sometime after K3 is on board satellite equipment operational, K4 can be co-located redundancy, the use of switchable with K3 (subject to FCC approval), attentuators on the uplink to operating 32 transponders from the accommodate a variety of earth same orbital location, achieving an station transmit power capabilities even higher level of protection. In and a satellite protection plan order to co-locate K3 and K4, the (described below) that calls for satellites need to be clones. spare satellites (in-orbit and on Alone, each satellite has the the ground) to protect against the highest ratio of redundant spare­ unlikely event of a catastropic parts to active-parts of any satellite failure are all additional satellite placed in-orbit to date. features of the satellite and When K3 and K4 are co-located, the satellite system that were designed sum of their spare TWT amplifiers, to meet the needs of the CATV and receivers, etc., is virtually the SMATV industry. equivalent of a spare satellite. If a problem occurs, on-board spare equipment can be called upon to

1987 NCTA Technical Papers-271 replace practically 50% of the along the signal path and the critical parts on either satellite. increase in system noise temperature caused by the warm rain. This total If it becomes necessary to replace signal degradation due to rain is any of the orbiting satellites, a called Rain Loss and is given by: compatible ground-spare satellite, constructed along with the active Rain Loss = satellite, will be readied for A + lOlog[l + ;:o (1-10-.lA)] dB ( 2) launch.

The costs of the in-orbit and where Ts is the clear sky system ground-spare capability are shared noise temperature (°K) and A is the among all the users of the entire signal attentuation (in dB) caused RCA satellite system, thereby by the rain as calculated in minimizing costs to each. Equation ( 1) .

The rain regions of the world and KU-BAND CHARACTERISTICS AND SYSTEMS the United States have been ------C-ONSIDERATION~------identified and characterized as shown in Figure 5. For a given power radiated from the satellite, the earth station size For a given earth station site, the and receive noise temperature (G/T rain rate statistics appropriate to needed) is determined by the the rain region in which the site is performance required (the video located are used. The elevation signal-to-noise ratio) and the angle to the satellite is determined availablity or the fraction of time and the rain attentuation and the this performance will be provided. Rain Loss are computed as in The availability is a function of equations 1 and 2 above. equipment availability and propagation effects. The major The carrier-to-noise ratio under propagation effects on satellite rain conditions is related to the links at Ku-band are due to rain. clear air carrier-to-noise ratio by (The largely ignored effects of sun the following: outage at C and Ku will be discussed later.) These effects lead to the C/Nrain C/Nclear Rain Loss attentuation of the signal propagated through the atmosphere Figure 6 shows the rain loss for a and an increase in the receive number of cities for a system noise system noise temperature due to the temperature of 290°K for the warm rain. satellite located at 85° West Longitude. The total attentuation of the signal (expressed in dB) over the earth­ The information contained in the space path is of the form figure is the margins needed to accomodate the atmospheric effects A o( L ( 1) of signal fading and increase in the receive system noise temperature at Where o( is the rain attenuation in various locations throughout the dB/km and L is the effective path country. The margins needed have length through the rain. been combined with the EIRP values for Kl and K3 to obtain the video The effective path length depends on signal-to-noise ratio versus the elevation angle of the receiving availability across the United antenna and on the rain rate. For States for a given antenna size. low rain rates, such as 5 to 10 mm/hr (light rainfall), L is the These results have been plotted for true path length through the rain, Kl on the contours shown in Figures while for high rain rates such as 7. The results for K3 (with 60 watt over 40 mm/hr (heavy rainfall), the transponders) are plotted in Figures non-uniform nature of the rain storm 8 and 9. requires an empirically determined correction factor to compute the SIGNAL OUTAGE AT KU-BAND effective path length. Discussions of Ku-band delivery The degradation of the received C/N systems inevitably turn to the topic is a result of the signal of rain outage or rain fades. The attentuation caused by the rain general perception is that Ku-band

272-1987 NCTA Technical Papers is plagued by significant rain life, affecting C and Ku-band outages (program distruptions) and systems to differing degrees. that C-hand is not. In fact, this is the most often used argument Table 1 shows the number of minutes against using Ku-band frequencies over a year the received video for distribution to CATV and SMATV signal to noise will fall to 45dB or systems. less for a 4. 5 meter C-hand TVRO receiving a signal from RCA Satcom Most of the force of this argument F3R and 1. 8 meter and a 3.1 meter has been eliminated by the design of Ku-band TVRO receiving a signal for the K3/K4 satellites and the RCA Kl in full conus mode. As inclusion of sun outage into overall defined for rain outage, a video S/N availability or outage calculations of 45 dB or less caused by sun for C and Ku-band systems. degradation is considered an outage. Using Kl in CONUS mode is a worst Most of the experience with Ku-band case situation since K3 provides rain outage was gained on first over 1. 25 dB more margin in CONUS generation Ku-band satellite mode than Kl and an additional 2. 5 systems. These systems used 10 watt dB of improvement over CONUS when cr 20 watt satellites and spread operating in the East or west beam this relatively low power across all modes. 48 states. Receiving systems, using first generation electronics, incorporated low noise amplifiers TABLE 1 with noise figures of 3dB or larger MINUTES OUT OF THE YEAR THAT S/N (the smaller the noise figure, the FALLS TO 45 DB OR LESS DUE TO SUN better the performance). The result OUTAGE ONLY was very low rain loss margins resulting in the rapid onset of signal degradation under rain C-hand (4.5 meter TVRO, conditions. RCA Satcom 3R) 138 minutes

The K3/K4 satellites are designed to Ku-band (1.8 meter TVRO, improve the rain loss margin. Each RCA Kl CONUS) 22 minutes satellite carries sixteen 47 watt transponders (60 watt transponders (3.1 meter TVRO, with FCC approval) . The result is RCA Kl CONUS) 20 minutes about 4-7 dB of improvement in margin over the 10 or 20 watt satellites when K3 or K4 are in full conus mode and about 6.5 - lOdB of Table 1 clearly shows that the C­ improvement when K3 and K4 are in hand TVRO experiences significantly half conus mode. A typical more sun outage than the K-Band receiving system today includes TVRO. The availability for this C­ antennas with an efficiency of 65% hand system can be shown to be or better, resulting in a higher 99.97%. The availabilities shown in antenna receive gain, and a LNB with Figures 7, 8 and 9 for various Ku­ a typical noise figure of 2.5 dB or band receiving systems demonstrate better. there is very little difference between C and Ku-band availability. These improvements in satellite and TVRO performance have dramatically increased the amount of rain fade KU-BAND RECEIVING SYSTEM DESIGN that the system can tolerate before signal degradation becomes a System Design problem. Given the inescapable benefits of A factor almost always overlooked Ku-band delivery, the optimized when discussing signal availability satellite operating characteristics is sun outage. Sun outage occurs and the unrivaled protection plan twice a year in the Fall and Spring offered by the satellite system, for a total of 18 - 20 days. Sun close attention must be paid to the outage occurs when a given receiving TVRO system to ensure that the TVRO, the satellite and the sun line installed ground segment does not up. Our ing these occasions, random become the weak link in the overall noise from the sun, to varying system. amounts degrades the received video signal. Sun outages are a fact of Program distribution to CATV and

1987 NCTA Technical Papers-273 SMATV systems requires very careful signal exhibiting a S/N of less than system design, installation and 45 dB. A 45 dB video signal is operation to ensure continued high still a very acceptable picture and performance. provides plenty of margin from that point to where the picture is Crimson Satellite Associates have actually unusable. If a lower S/N identified certain performance is used as the outage criteria, requirements to be achieved by TVROs system availability improves. utilized to receive the Kl and K3 distributed programs. See Table 2. The selection of Ku-band TVROs The TVRO systems distributed to distributed by HBO and RCA Americom cable systems by HBO and RCA was made as follows: American Communications, Inc. ("RCA Americom") were selected to conform From the requirements of Table 2, to these performance requirements. the Rain Loss for multiple sites in each rain zone was calculated. This Rain Loss described the amount of ------'rABLE 2------margin between clear sky performance SIGNAL AVAILABILITY AND OUTAGE and the defined outage to be DEFINITION FOR RAIN LOSS ONLY provided by the TVRO. Equation 3 and 4 were then used to calculate Signal availability CATV : the required TVRO gain needed to 99.99% (goal) provide that margin. Signal availability SMATV: 99.9% C/N = S/NV - RTF (3) G = C/N - EIRP + Ls + Lp - 228.6 + Signal outage occurs when: l~log Ts + Rain Loss S/N Video equals or falls + lOlog B ( 4) below 45dB Where:

Clear sky S/N Video RTF Receiver Transfer Function GA Antenna Receive Gain 50 dB or better Ls space Loss Lp Pointing Loss Ts System Noise Temperature Signal availability, as previously B System Noise Bandwidth described, is the percentage of a year that the signal received by a Note that the required gain was CATV or SMATV TVRO exceeds the calculated for the worst case specified outage threshold level. operational conditions; Kl EIRP in From the above table, a CATV system full CONUS mode on the lowest should provide to the extent powered transponder. Half CONUS possible a video signal with a S/N mode operation will only improve greater than 45 dB 99.99% of the availability. Also, K3 provides an year and an SMATV system must increase in CONUS and half CONUS perform to that extent 99.9% of the EIRP compared to Kl, thus improving year. In other words, a CATV system performance further. should have an outage as defined in Table 2 of no more than 53 minutes If the calculated gain did not out of the year and an SMATV system achieve at least a 50 dB Video S/N for no more than 530 minutes out of under clear sky conditions, the gain the year. Two very important points of the system was increased must be recognized and considered accordingly. Available TVRO when evaluating the signal components were then selected to availability requirements in Table build the required TVRO system. 2. First, the availablity here refers only to signal degradation Figures 7, 8, and 9 show the caused by rain or atmospheric required antenna sizes for a given conditions. It does not include availability for Kl and K3. other system induced degradations such as sun outage. Secondly, the The 22 minute sun outage discussed teim outage as used in this analysis earlier reduces the availability is misleading. For the purpose of shown by .0042%. conservative system design and to insure system margin, a signal System Installation and Operations outage is defined by Crimson Satellite Associates as a video Ku-band TVROs require slightly more

274-1987 NCTA Technical Papers care with installation and operation However, the result of antenna than a C-band TVRO. While the misalignment is to cause the system special requirements are not margin to be reduced. The reduced onerous, they must be recognized if margin in turn causes the defined the systems are to perform at outage level to be reached quicker maximum capacity. than predicted, thus reducing the signal availability. The wavelength of a Ku-band signal is about 1/3 that of a C-band It is recommended that the operator signal. This means that the main align his Ku-band TVRO using a field beamwidth of a Ku-band antenna is strength meter or if possible a about 1/3 the beamwidth of a C-band spectrum analyzer instead of viewing antenna of the same size. The the received picture quality on a TV reduced beamwidth imposes a set. Additionally, as with C-band requirement to aim the Ku-band TVROs, the antenna alignment should antenna more accurately than a be peaked periodically when the comparable C-band antenna and to satellite is in the center of the hold the antenna as still as box. possible. Movement of a CATV or SMATV Ku-band antenna can cause a signal degradation of 2 or 3 dB. CONCLUSION This amount of degradation is not critical under most operating This paper has attempted to conditions but it does reduce the familarize the reader with Ku-band system rain loss margin. satellite requirements, the Additionally the reduced wave advantages of Ku-band distribution lengths of Ku-band frequencies and system operating considerations. requires the antenna reflector surface smoothness to be held to a Ku-band provides: (1) the tight tolerance and the shape of the opportunity to operate a TVRO in an antenna be as close as possible to interference free environment thus the required parabolic shape. opening up additional business opportunities; ( 2) unheard of The installer of a Ku-band TVRO must protection against business take steps similar to the one he disruption and ground segment would take when installing a C-band disruption in the event of a TVRO to ensure the pad and all satellite failure; ( 3) video signal reflector mounting hardware is rigid performance superior to C-band for and capable of holding the reflector comparible antenna sizes; and (4) as motionless as possible in signal availability equivalent to expected wind conditions. Also, C-band when both rain fade and sun during reflector assembly, care must outage effects are considered. be taken not to distort the reflector surface by over torquing The C-band satellites used by the bolts or denting or bending the cable industry reach the end of reflector. their design lives by 1992. Therefore, 1987 is the year to Antenna pointing and polarization focus on the transition to the next alignment of a Ku-band TVRO is generation of satellites. A short similar to that of a C-band TVRO. term re-location to a satellite with However, because of the very high 2 or 3 years additional life is not S/N of the video signal received a solution. In fact, it puts the under most conditions, the installer industry at a competitive can be misled about the accuracy of disadvantage with the evolving his alignment efforts. A Ku-band technology and actually presents the TVRO, under most operating risk that a launch opening will not conditions, produces a video signal be available when a successor far superior to that produced by a satellite needs to be launched. comparable C-band system. In fact, the quality of the received picture The satellites of the future will be is so good that even a 2 or 3 dB state-of-the-art Ku-band. They will degradation in the received signal be capable of affecting both cable C/N due to antenna misalignment is operators' and programmers' not noticable by viewing the picture on a TV set.

1987 NCTA Technical Papers-275 businesses and may be operated by companies with little or no investment in our business. The cable industry cannot afford to restrict itself to yesterday's technology. Today, with Ku-band technology, we have the opportunity to maintain a competitive technological edge - an opportunity that has come at a time that is a natural decision juncture for satellite capacity planning.

276-1987 NCTA Technical Papers FIGURE 1* EIRP CONTOURS (dBW) FOR EAST BEAM

:: ~.---~=- ._:~..:..:;:;.~~;;-,~-:7~ •eo~-...... ,..,.; 490----~~~~~~ 50 o--..,...,..;.;'-:1'--1

FIGURE 2* EIRP CONTOURS (dBW) FOR WEST BEAM

FIGURE 3* EIRP 20NTOURS FOR CONUS

*CONTOURS FOR 60 WATT TRANSPONDERS (PENDING FCC APPROVAL). 47 WATT TRANSPONDERS' CONTOURS ARE REDUCED BY ABOUT 1 dB FROM THOSE SHOWN.

1987 NCTA Technical Papers-277 o rd-,d-,rdnrcb-m:&-,rdn~~ 1A 3A 6A 7A aA 1 lA 13A 1SA SAT A 2 4 6 8 10 12 U 16 {Sd ~~~n?n~:p11Sfr-9.rSn 1 3 5 7 v 11 13 15 VER. rC::3l r-t:Jl rbrr:DlrU:nnblrt:nrbl 1e Je sa 7B as 11a us 1sa SAT. 8 2 • 6 I 10 12 14 16 { n::::nrc::T-ln::::Jnrd-lrdnr5nrenrdn HOR. 28 48 68 BB 109 128 148 168

1\.7 Gl-(r

CHANNEL NUMBERS 1·16 INDICATE WIOEBANO ~ J.IIH: CHANNELS

CHANNEl. NUMBERS 1A·16A AND 18·168 INDICATE NARROWBAND 27 MHz CHANNHS FOR SATELLITE A AND B RESPECTIVELY ~71~ K3/K4 CHANNELIZATION PLAN FIGURE 4

- :M P.• : .. ... r..:.. rr ~:. C! ·,~ r:c SA..,..E: ... UTE A'T 8:;, 0~·, RECl VE SYST£~1 TF " PERATLRE - :ro'-'1< 25-,------,------,------,

20-r------r------r------~

PROBABILITY OF RAIN LOSS >VALUE

RAIN LOSS AT VARIOUS CITIES FIGURE 6

278--1987 NCTA Technical Papers FIGURE 7

ANTENNA SIZES TO ACHIEVE 99.9~ AVAILABILITY

CONTOURS

+ 1.8 METERS 3. 7 METERS

3, 0 METERS X 5. 5 METERS

FIGURE B

ANTENNA SIZES TO ACHIEVE 99.9~ AVAILABILITY WITH K3 FULL CONUS

CONTOURS

+ 1.8 METERS 3. 7 METERS

3. 0 METERS X 5.5 METERS

FIGURE 9 ANTENNA SIZES TO ACHIEVE

CONTOURS'

+ 1.8 METERS 3, 7 METERS

J, 0 METERS X 5. 5 METERS

1987 NCTA Technical Papers-279