Table
of Contents:
1.
Abstract
2.
Background
3.
Optimizing Use of GOES-3 for the Short- and Intermediate-Terms
4.
GOES-3 Services Improvement Plan
5.
Implementation Phases
6.
Implications
7.
Summary
Endnotes
1. ABSTRACT
The Pan-Pacific Education and Communications Experiments by
Satellite (PEACESAT) Program, sponsored by the U.S. Congress and
the Department of Commerce's National Telecommunications and Information
Administration (NTIA), was re-established in 1989 through the
use of the National Oceanic and Atmospheric Administration's (NOAA)
GOES-3 satellite. Since its formal opening in 1992, the PEACESAT
regional telecommunications
alliance has grown to 36 sites in 25 countries.
The objectives of this paper are to provide a brief overview
of the program, review some of its current challenges, and describe
how the PEACESAT program is preparing to meet these challenges.
The paper describes PEACESAT's plan to meet the needs of users
in the short and intermediate-term. The plan calls for PEACESAT
to optimize the use of the GOES-3 capacity by increasing the
number of analog carriers,
establishing a digital carrier
network, applying technologies that optimize the use of full
duplex channels for concurrent voice and data communication,
and to establish multiple video teleconferencing channels. PEACESAT's
plan will constitute a major transition of the telecommunications
alliance.
2. BACKGROUND
The PEACESAT program was initiated in 1971 to experiment with
distance learning, emergency information, and teleconferencing
applications through the use of a single push-to-talk voice
communication using the
ATS-1 satellite by sites in the Pacific(1). In 1985, the PEACESAT
program became temporarily limited when the ATS-1 satellite
ran out of fuel and could no longer support the needs of its
users(2). The program was re-established by United States Congress
through the efforts of Senator Daniel Inouye of Hawaii, NTIA,
users, and the University of Hawaii(3). The missions, re-establishment,
use, and potential of PEACESAT are discussed in several documents
and reports and are not described in this paper(4).
The re-establishment was made possible through repositioning
of the National Oceanic and Atmospheric Administration's (NOAA)
geostationary weather satellite,
GOES-3, in 1990. GOES-3 was one of a series of satellites used
by NOAA for weather data gathering(5). Through the repositioning
of the satellite, the GOES-3 footprint covers parts of the West
Coast of the USA, most of the Pacific Rim, and all of the Western
and South Pacific Islands countries.
Since the PEACESAT program was formally re-established in 1992,
the growth of the network has been tremendous. As of November,
1993, 36 sites in 25 countries have acquired terminal equipment
(antenna, power, transceivers) to access voice and data services
throughout the Pacific. There are also 20 additional sites that
have committed to come on-line in the Federal Fiscal Year 1993/1994
(October 1, 1993 to September 30, 1994)(6). In addition, more
sites are considering becoming part of the PEACESAT network.
2.1 Challenges
The re-establishment of PEACESAT has occurred smoothly and the
program is providing services as planned and designed. PEACESAT
has also received enthusiastic support from its users in the
Pacific.
At the same time that the re-establishment may be viewed as
a success, PEACESAT faces several challenges. One challenge
centers around how PEACESAT will meet the increased demands
by users for more full-duplex
data access, concurrent voice/data services, and video teleconferencing
based educational services. A second challenge is how PEACESAT
should maintain, strengthen, and extend services in the short-
and intermediate-terms. A third challenge for PEACESAT is the
selection of a long-term satellite solution that can support
the needs of PEACESAT.
2.1.1 Level of Services and User Demands
One of the pressing challenges for PEACESAT is the level of
services that are provided through the GOES-3 satellite system.
Island governments, educational institutions, regional organizations,
and other users have made their needs known to NTIA and PEACESAT.
In the near term, PEACESAT users desire access to increased
data channels and are requesting concurrent access to dedicated
data channels. Some users also are requesting concurrent voice,
data, and compressed digital video. Over the long-term, PEACESAT
users desire high speed data networking and full-motion video.
2.1.2 Short and Intermediate-Term Solutions
Until a long-term solution is developed, there is a need to
meet the needs of users during the short and intermediate terms.
This challenge is directly addressed in this paper and may be
achieved by optimizing the use of the existing GOES-3 satellite.
This approach is consistent with NTIA's recommendation issued
in a 1992 report which states that: "NTIA should work toward
extending PEACESAT's use of the GOES series of satellites to
provide more time to search for the long-term satellite configurations
[to meet the needs of users]."(7)
2.1.3 Selection of a Satellite for Future Programming
The selection of a satellite to provide long-term services is
important for two reasons. First, the agreement between NTIA
and NOAA to use GOES-3 will end in 1995 even though there are
indications that the agreement will be extended for the life
of the satellite. Secondly, and just as important, the GOES-3
satellite will probably run out of fuel sometime around the
Year 2000 and is expected to have problems in maintaining its
geostationary orbit. Finally, there
are inherent limitations in the capacity of the GOES system
to meet the growing needs of its users.
In response to this challenge, NTIA and PEACESAT have initiated
studies to define user needs and alternatives for providing
a long-term satellite system for PEACESAT. The selection of
an alternative satellite to deliver the services is critical
to the long-term success of the PEACESAT program. The studies
by NTIA and PEACESAT have been documented most recently in a
December, 1992 report issued by NTIA entitled PEACESAT: Communications
Satellite Services for the Pacific Islands: Satellite Feasibility
Study(8). Although the report does not contain recommendations
for a long-term solution, progress toward analyzing alternatives
has been made.
2.2 NTIA and PEACESAT Assessments of User Needs
NTIA and PEACESAT have been continuously working toward identifying
and defining the needs of users. This is always a critical but
difficult task. Identifying requirements is important since
they impact the definition of alternative solutions. At the
same time, defining user requirements is difficult since users'
needs are dynamic and change with experience, environmental
factors including budgets, and developments in technology. The
NTIA and PEACESAT reports describe some of the user requirements
in the near- and long-term future (2007) and include:
- Increased
data circuits for Internet and
other data driven information services;
- Concurrent
voice and multiple data access support;
- Channels
for sensitive voice and data communication;
- 64
Kbps transmission for higher speed data transfer;
- Compressed
video teleconferencing;
- High
Speed data communication;
and,
- Full
motion video.
Based on the report and response from users, the long-term needs
for improved communication
services to the Pacific will require significant communication
capability, and some requirements such as full-motion video may
never be able to be delivered through a PEACESAT type program,
with the exception, perhaps, of public broadcasting video. These
general needs will be further studied to determine their relative
importance.
In the short and intermediate-terms, it is clear that PEACESAT
needs to provide concurrent voice and data services, and support
concurrent data access services for information access.
Since introducing data services, the needs and demands for data
access have grown steadily. The anticipation over the introduction
of Internet services and other
planned data-driven information programming (BBS) has been overwhelming.
PEACESAT needs to improve access to the high-volume usage areas.
It is hoped that these users will be able to access data-driven
information services on an ongoing basis without operator assisted
circuit switching that
in itself does not optimize data transmission.
Any user of Internet or other
on-line information services knows the problems of trying to
schedule time for the use of such circuits.
A reservation system may be initially acceptable, but it will
not be acceptable for long, especially when the service is shared
by 35 different sites. The contention for the use of the channel
has already resulted in conflicts between and among voice and
data users. The conflicts are expected to grow.
More and higher speed digital channels are also needed since
compressed digital video transmission may be important to the
overall development of the PEACESAT program given its current
mission (e.g., telemedicine applications and distance education).
It may become even more important as PEACESAT provides support
for the promotion of regional economic development activities.
2.3 PEACESAT Program Priorities
PEACESAT, as with any other program, must, of course, prioritize
where it will concentrate its resources. Any PEACESAT program
activity must be guided by a set of priorities. NTIA suggests
the following priority scheme for PEACESAT to use in its program
planning:
-
Maintain existing services;
-
Strengthen existing services;
-
Make existing services more widely available (both to current
users and new users); and,
-
Develop new services(9).
The priority scheme implies that PEACESAT plans to improve services
in a way that maintains the existing services, strengthens them,
and increases their availability to the Pacific Basin and Rim
before introducing new services. The priorities are reasonable
given limited budget and satellite resources.
3. OPTIMIZING USE OF GOES-3 FOR THE
SHORT- AND INTERMEDIATE-TERMS
Until a long-term satellite solution is found to meet the needs
of the Pacific Basin and Rim, GOES-3 could be used to provide
improved voice, data, and compressed video service for the short-
and intermediate- terms.
The PEACESAT/GOES-3 transponder operates in S and L Bands and
has an 8 MHz bandwidth (2025-2033
MHz Transmit and 1683-1691 MHz Receive). The current voice and
low-speed data carriers are
16 KHz and are spaced 50 KHz apart. A full-duplex
channel uses two of these carriers.
The capacity of the GOES-3 transponder is not being fully utilized.
There is additional carrier and bandwidth
capacity that could potentially be used by PEACESAT to meet
the needs of users in the short- and intermediate-term. There
are also technologies that may be used to optimize the use of
the carriers. The following
is a brief discussion of how these opportunities could be realized
by PEACESAT.
3.1 Increasing Number, Type, and Capacity of GOES-3 Carriers
PEACESAT could increase the number, type, and capacity of GOES-3
carriers.
3.1.1 Increase the Number of Analog Carriers
PEACESAT could increase services to meet the demands of users
by increasing the number of analog
carriers and to increase the accessibility to these carriers
by remote sites.
The current design of the PEACESAT mesh
network means that users can only transmit a single carrier
that can support either a simplex
voice or a full-duplex voice/low
speed (9.6 Kbps) data link. The design allows Pacific Island
and Rim sites to communicate with each other through 9 existing
simplex carrier
circuits and 3 full-duplex
carrier circuits.
The full-duplex carriers
support low-speed (9.6 Kbps) data.
The design provides the benefits of inter-networking many different
locations throughout the Pacific using a minimum number of carriers.
The downside of the system is that: (1) the carriers
only support a single use, (2) 35 PEACESAT sites must share
only 3 full-duplex circuits,
and (3) PEACESAT Headquarters (PHQ) currently only has 1 transceiver
that can be used for data purposes. To improve access to more
GOES-3 full-duplex carriers,
PEACESAT could modify the terminals to access new analog
transmit/receive carrier frequencies.
3.1.2 Increase the Number of Concurrent Carriers
at PEACESAT Headquarters (PHQ)
Increasing the number of analog
carriers that can be used by
PEACESAT sites will not by itself resolve the problem of concurrent
data access to PEACESAT Headquarters. The use of the current
3-Meter antenna and power amplifier inherently limits the number
of carriers that can be handled
by PHQ. These antennas and power amplifiers were designed to
support a single analog carrier.
Since PHQ has two antennas, it can currently have two simultaneous
sessions. However, if PHQ has a voice conference and data session
established, it will not be able to provide any hub
administrative services such as contacting users of impending
meetings.
PEACESAT could increase the number of carriers
that PHQ can receive and transmit to in order to provide concurrent
access to multiple voice and data channels.
There are two alternatives by which this could be accomplished.
First, PEACESAT could install a new terminal (antenna, power
amplifier, indoor electronics) for each channel
that PEACESAT wants to establish. This would create an antenna
farm and is not very practical given the space and cost factors.
Second, PEACESAT could upgrade the size of one of its existing
antennas, purchase a new power amplifier, and install a rack
mounted GOES-3 transceiver channel
bank to save space and power. Increasing the size of the antenna,
power amplifier, and installing a transceiver bank clearly appears
the better solution when compared to installing an antenna farm.
3.1.3 Establish a Digital Carrier Network
Increasing the number of analog
carriers and increasing the
capability of PHQ to concurrently support multiple carriers
will not solve the needs of certain sites to transmit voice
and data simultaneously.
To resolve these problems, PEACESAT could establish a digital
carrier network concurrent with
the existing analog FM network
to increase the capacity to support multiple voice, data, and
compressed video channels by sites. By creating a digital carrier
network, PEACESAT may be able to support the simultaneous transmission
of voice, data, and possibly compressed video communication.
Digital carriers are generally
favored over analog FM modulation
since it is more cost-effective in the use of satellite resources.
Naturally, there are limitations to the number and capacity
of digital carriers that can
be established. The limitations will depend largely on the power
budget, bandwidth, capability
of the satellite transponder, and potential impact on the analog
carriers.
3.1.4 Compressed Video Mesh
Network Carriers
Digital carriers capable of
supporting 64+ Kbps could be established to support compressed
digital video applications. It may be possible to design the
use of the carrier capacity
of the GOES-3 to support a single digital carrier
with a data rate of up to 768 Kbps. The question is what data
rates should PEACESAT support for compressed video teleconferencing
given the other needs for voice/data.
3.1.5 Planning Model for PEACESAT
Table 1: Capacity Planning Model shows the number and capacity
of various carriers that could
potentially be established using the 8 MHz bandwidth
of the GOES-3 satellite. The table presumes that there is about
1.5 Mbps of digital capacity available for use. This is equal
to about 768 Kbps in full-duplex
mode.
Table 1: Capacity Planning Model
________________________________________________________________________
|Carrier Type | Quantity |
|________________________|_______________________________________________|
|Analog FM | Existing 9 Analog Simplex for Voice and |
| | 3 Analog Full-Duplex for Voice/Data |
|Analog FM | Potential New 10 Analog Simplex for Voice |
| | or 5 Analog Full Duplex for Voice/Data |
|Voice/Data Digital | Potential New |
|RF | 8 to 16 -- 32 Kbps FD Channels |
|Digital Video | Potential New |
|Digital RF | 2 -- 128+ Kbps FD Channels |
|________________________|_______________________________________________|
The planning model shows GOES-3 potentially supporting about
10 new analog FM carriers
and 16 digital carriers with
32 Kbps capacity. The model also shows GOES-3 supporting 2 new
digital carriers that have 64/128+
Kbps in carrier capacity for
compressed video or higher speed data transfers. If these capacities
can be realized, then, GOES-3 could potentially strengthen existing
services and make them more widely available to meet the needs
of the Pacific Islands and Rim. The extent to which GOES-3 can
meet these needs will be subject to philosophy, technical system
constraints, design, and costs.
Digital bandwidth tests on
GOES-3 have been conducted by MAS with 64 Kbps channels. The
success of the tests show that higher bandwidth
carriers could be established
and supported using the existing 3-Meter antennas and 50W power
amplifiers(10). However, the planning model is theoretical and
the real questions remain:
-
How many concurrent analog
and digital carriers can be
supported for enhanced services?
-
What digital data rates can the digital carriers
support?
-
How can these carriers best
be used?
3.2 Optimization of Carrier Capacity
Presuming that a digital carrier
system can be established using the GOES-3 satellite, there are
several technologies that could be used to optimize the voice,
data, and compressed video communication
over the digital carrier. The
optimization may be realized by using voice compression, data
concentrators, and a Digital Bandwidth
Manager (DBM) that supports different digital transmission
schemes such as circuit, packet, and frame relay over digital
channel capacities less than 256
Kbps.
3.2.1 Voice Compression
Voice can be converted into digital data through pulse code modulation
that can then be "compressed" through bit sampling algorithms.
The "compressed voice" is then communicated as digital
data streams from one site to another. When decompressed, the
data is converted back into audio voice signals.
Today, some vendors have acceptable quality voice carried over
a CELP bit sampling algorithm requiring 4.8 Kbps of transmission.
By compressing the voice to lower bit
rates, it is possible to carry more voice channels on a
carrier. For example, a single
full-duplex digital circuit
capable of supporting 9.6 Kbps can provide 2 voice circuits
at 4.8 Kbps, assuming that bandwidth
is used for in-band signaling.
3.2.2 Data Concentration
The current use of a 9.6 data channel
over a full-duplex analog
carrier by a single user is
not an efficient use of the GOES-3 resource. To make better
use of the available bandwidth,
data multiplexing technologies could be used to share resources
among more users. X.25 packet data switching
could be effectively deployed by PEACESAT to enable more users
to share full-duplex data
channels for access to on-line and Internet
services.
Response time and throughput in an X.25 network is dependent
on the number of concurrent users and best applied in an on-line
data access environment where users interact with host system(s).
X.25 is not optimized for bursty data and large data file transfers.
Response time should not be a problem for many PEACESAT
Sites that are limited through the "land line"
connections to lower speeds. Response time could become a problem
for users with good telecommunication local land lines and are
doing large data file transfers.
3.2.3 Voice and Data Multiplexing
Since both data and voice can be compressed as digital data,
it is possible to use a single digital transmission carrier
to carry multiple channels of digital voice and data traffic.
The capacity of the transmission
facility, level of voice and data compression, nature of
application, and quality of voice acceptable will determine
what the usefulness of a transmission
facility for a particular application.
To optimize the use of a digital channel,
PEACESAT could use a Digital Bandwidth Manager (DBM) to transmit
simultaneously compressed voice and X.25 packet switched data.
Using technologies that are commercially available, it is possible
to share a 19.2 Kbps digital channel
to support 2 voice (at 4.8 Kbps) and multiple data users concentrated
through X.25 packet switch through a DBM.
This basic approach is well established through many different
vendor technologies and allows further optimization of voice
and data communication
over scarce PEACESAT carrier
resources. Some vendor systems can take multiple analog
voice inputs, digitize the signals, and apply a compression
algorithm for the voice and concentrate data transmissions.
This enables, depending on the voice and data compression algorithm,
the systems to transmit multiple concurrent voice sessions over
a 14.4 Kbps and higher full-duplex
channel.
These systems can further route the voice as circuit data and
packetized X.25 data to the destination. The routing for data
is dynamic. Depending on the capacity of the full-duplex
channel and the level of technology
that is deployed, the routing of the voice traffic can be done
dynamically or through an external switch.
3.2.4 Video Compression and Higher- Speed Data Channels
Once a higher speed digital carrier
is established, it can be used to support compressed video and
higher speed data file transfer applications.
The DBM could also be used for routing of nx64 Kbps data. Support
for fractional T-1 services is important for higher-speed data
file transfers and for compressed video. The CCITT has developed
standards for video transmissions based on "px64"
digital data rates.
Sites that may have more than one location that need to be inter-networked
for compressed video would be served best through a single communication
technology that can redirect the signal to multiple interface
channels. A PEACESAT Site, for
example, might have a need to establish a video
conference session with another local site through a microwave
network as well as through the PEACESAT network. A DBM with
the ability to route the px64 video codec traffic from one channel
interface to another would be useful and minimize the amount
of manual rewiring that may need to be undertaken.
4. GOES-3 SERVICES IMPROVEMENT PLAN
PEACESAT has proposed a GOES-3 Services Improvement Plan (SIP)
to NTIA. The plan calls for PEACESAT to: (11)
-
Maintain 9 current carriers
for command, voice mesh network
and 3 full-duplex channels
for data applications (The number of analog
carriers may be reduced and
replaced with mesh network digital
data carriers);
-
Establish a digital network hub
that can support concurrent voice and data uses between a
minimum of 10 sites in the Pacific and PEACESAT Headquarters;
-
Introduce integrated voice, data, and 64+ Kbps digital
bandwidth managers to optimize the voice, data, and compressed
video communication
uses enabled by the digital carriers;
-
Establish a voice bridge between mesh
network and digital network carriers
for voice communication;
and,
-
Establish multiple digital carriers
capable of supporting a minimum of 64 Kbps for compressed
video applications.
From a program perspective, the PEACESAT design maintains existing
services, strengthens existing services by improving their operation
(e.g. concurrent voice/data and concurrent data access from
sites), and makes the services more widely available to PEACESAT
users by providing concurrent access to more users at sites.
The design also enables more sites to become part of the mesh
network may be Internetworked
with other systems and networks through the Pacific Basin and
Rim such as the Japanese ETS-V and the State of Hawaii's HAwaii
Wide Area Integrated Information Access Network (HAWAIIAN).
From a technical perspective, the design is based on the strategy
of supporting and enhancing the existing analog
services network while taking advantage of the capacity of the
GOES-3 satellite through establishing a digital data network
with a hub at PHQ. The design also
includes a capacity for new services such as compressed digital
video teleconferencing in a cost-effective mesh
network design.
5. IMPLEMENTATION PHASES
The overall project plan calls for PEACESAT, NTIA, AND MAS to:
-
Develop the GOES-3 Services Improvement Plan
-
Develop PEACESAT Partners and Participants
-
Install an 8.5-Meter Antenna (Power amplifier, etc.) at PHQ
-
Install a Transceiver Bank and Testing of 19.2 Kbps Analog
or 32 Kbps Phased Shift Modems
-
Operationalize Data Services
-
Install a 6-Meter Dish at MAS
-
Conduct Satellite Transmission Tests
-
Install Digital Bandwidth Managers
-
Conduct Voice, Data, and Compressed Video Tests
-
Develop GOES-3 Services Deployment Plan (Including Frequency
Allocation)
-
Deploy the Network
The implementation of these tasks could be accomplished in three
phases. Phase I would increase the number of full-duplex
carriers that can be simultaneously
received at the PEACESAT hub and for testing the capacity and
the ability of the 19.2/32 Kbps full-duplex
carriers to handle multiple
channels of concurrent voice and data over limited bandwidth.
Phase II would focus on the experimentation and testing of the
various transmission resources of GOES-3 and to test the ability
of the terminals to support voice, data, and compressed digital
video at various capacities.
Phase III would focus on the deployment of the services based
on the results of Phase II.
6. IMPLICATIONS
There are several implications that will arise from the conceptual
design of the GOES-3 SIP. These implications need to be considered
in the final design and implementation of the plan.
6.1 User Groups
Establishing a digital or star network design to complement
the existing PEACESAT mesh network
will create two basic types of "users." One group
of users will use the analog
"mesh" network. A second
group of users will be linked to the PHQ in a digital star or
hub and spoke network. All sites
using the digital services will have multiple concurrent voice
and data services and be internetworked to the mesh
users through bridging at PHQ.
The creation of different "user groups" may create
an impression that there are different "classes" of
users in PEACESAT. The concept of "classes" may be
viewed from at least two perspectives. On the one hand, it could
be viewed as detrimental to the concept of PEACESAT, which has
historically stressed a system that provides the same capabilities
equally to its user community. On the other hand, the plan may
be viewed as a means of meeting the needs of different users.
It should be understood that users will select which user group
the site will participate in, constrained, of course, by the
number and capacity of digital carriers
that can be provided through GOES-3.
6.2 Cost of Network
There are cost implications of the proposed network for both
the PHQ and user sites. PHQ would need to install a larger antenna
and power amplifier, additional analog
and digital transceivers and RF modems, a bridge to interface
the analog and digital channels,
and the additional networking capacity to access other systems
and networks in Hawaii which users wish access to (e.g. UH libraries
system). PEACESAT would also need personnel and space to support
the technology upgrades.
PEACESAT sites, depending on the tests, will not need to upgrade
their antennas or power amplifiers for single 32 or 64 Kbps
channels. These sites would need to acquire a voice/data DBM
and the additional peripherals to support multiple concurrent
voice and data applications.
However, if a site requires use of higher-speed video channels
beyond 64 Kbps or concurrent voice and data with a 64 Kbps video
link, then, the site will incur additional costs. The major
costs that will be incurred by a site will be for a larger antenna
and power amplifier, and a voice bridge if one is not already
present. There will also be costs for interfacing the systems
to the local public service telephone network.
6.3 Technical
There are several technical issues that will need to be resolved.
The major technical issue is the number of digital carriers
and capacity that can be established without interrupting or
degrading the mesh network analog
carriers. Other issues include
the design of the terminals to support two digital and one analog
carriers, level of interference
with analog FM carriers,
how the mesh and star network voice
services would be bridged through the network, and whether the
DBMs will function the way it is currently projected over a
satellite carrier. None of the
issues are significant enough to invalidate the conceptual design
of the GOES-3 SIP. The major technical concerns revolve around
the ultimate capacity of the carriers
and design alternatives.
These concerns will be addressed in the Phase III GOES-3 Services
Deployment Plan that would be prepared at the conclusion of
the tests conducted in Phase II.
The technical issue of how the "mesh
network" user would interface to "digital" users
is one issue that merits some discussion here since a major
program objective is to enable sites to communicate with each
other. PEACESAT would need to bridge the analog
mesh network communication
carrier channels with the digital
voice carrier channel
through either a voice bridge or voice switch that supports
voice conferencing. The optimal solution will depend on PHQ's
other local telephone, data, and video teleconferencing bridging
requirements.
6.4 Operational Implications
There are operational implications that will also need to be
considered by PEACESAT. From a systems point of view, some of
the operational implications will include: network management
functions; bridging mesh with star
network voice; developing new scheduling systems for compressed
video programming; bridging pass-through communication
between Hawaii video
conference and HITS studios to the network, and so on. There
will be a measure of added complexity for the PHQ since the
technology that is being implemented is far more complex than
the technology being used today.
7. SUMMARY
The re-establishment of PEACESAT has been successful. However,
there is a need to extend and strengthen services to the Pacific.
The services requested by current PEACESAT users include more
voice and data channels, concurrent voice and data communication,
non-interrupted data services, higher bandwidth
data, and compressed video. Most important of these services
in the short-term is to provide concurrent voice and data access.
Although NTIA and PEACESAT are studying the long-term solution,
there are short- and intermediate-term steps that could be taken
to improve services. PEACESAT has developed a plan to provide
more analog carriers,
establish a digital carrier
network using the additional bandwidth
capacity, and optimize the use of the digital carriers
through multiple access digital telecommunication technologies.
PEACESAT, NTIA, and Marine-Air Systems are currently evaluating
this plan and may initiate trials to resolve outstanding technical
questions. The major technical question is the number of carriers
and the capacity of such carriers
that can be created.
Should these tests be successful, PEACESAT will be able to develop
and implement a service improvement plan to maintain, strengthen,
and extend existing services, and experiment with the delivery
of new services such as compressed video conferencing. Realization
of such a plan will effectuate a major transition in the regional
telecommunications
alliance called PEACESAT.
ENDNOTES
This paper is based in part on a report prepared for the PEACESAT
Program at the University of Hawaii by Norman Okamura entitled
Preliminary Assessment and Conceptual Design for the Use of
GOES-3 to Provide Improved Services to the Pacific.
The assistance and support of the personnel and consultants
of PEACESAT Headquarters in the preparation of this paper must
be acknowledged. This includes Lori Mukaida, Director, Christina
Higa, Operations Manager, Thomas Okamura, Programming Manager,
and Calvin Fujioka, Fiscal Specialist. I am particularly indebted
to Calvin for checking figures out and to Thomas for all of
the graphics. The paper has benefited substantially from the
discussion and dialogue that has been conducted with PEACESAT
during the past five months.
The contributions of Mr. Ray Jennings and Mr. Bill Cooperman
of the National Telecommunications and Information Administration,
as well as Mr. Peter Williams and Mr. John Yaldwin of Marine-Air
Systems must also be acknowledged since many of the ideas and
issues discussed in this paper were developed as a direct result
of issues raised and information provided by these organizations.
- The
PEACESAT program was initiated in 1971 with a single voice
channel on ATS-1. Cooperman,
W., Mukaida, L., Topping, D. 1991. "The Return of PEACESAT".
Proceeding: Pacific Telecommunications Conference. Honolulu,
Hawaii.
-
When the ATS-1 ran out of fuel in 1985, the PEACESAT program
continued operations at the University of Hawaii using a high-frequency
radio until Congress re-established the program.
-
The PEACESAT Program was re-established through a Congressional
appropriation to the U.S. Department of Commerce's National
Telecommunications and Information Administration (NTIA) in
1989. Funds are made available to the University of Hawaii
for the PEACESAT program through a PEACESAT Re-Establishment
Cooperative Agreement.
Once the Congressional budget has been approved, PEACESAT
will submit a proposed contract amendment to NTIA. As part
of the proposed contract amendment, PEACESAT will be proposing
ideas on how services may be improved in the Pacific through
the use of the GOES-3 satellite system.
-
See: Mukaida, L., Topping D. 1989. "Appropriate Technology:
The PEACESAT Experiment". Proceeding: Pacific Telecommunications
Conference. Honolulu, Hawaii;
Proceeding: PEACESAT Policy Conference. 1992. Sendai, Japan.
Mukaida, L. 1992.
"PEACESAT
Program Strategic Plan (Draft)", University of Hawaii,
Honolulu, Hawaii.
-
The GOES series of satellites was built by Ford and Hughes
and are used to transmit satellite imagery for weather data
gathering. The image camera and/or transmitter of the GOES-3
satellite became dysfunctional. GOES-7 also experiences the
same problem and may be possibly used by PEACESAT for other
purposes some time in the future.
-
The Federal Emergency Management Agency (FEMA) plans to install
14 PEACESAT terminals in the Pacific during FY 93/94. FEMA
became interested in PEACESAT as a result of its usefulness
during Hurricane Iniki.
In addition to the 14 FEMA sites, there are 6 other Pacific
sites that are planning to install PEACESAT terminals.
-
Cooperman, W., & Connors, D. PEACESAT: Communications
Satellite Services for the Pacific Islands: Satellite Feasibility
Study, (US Department of Commerce, National Telecommunication
and Information Administration, December, 1992. P.2.
-
Ibid.
-
Cooperman, W. "Re: GOES Improvement Plan". Memo
to: to Dr. Donald M. Topping, Principal Investigator, PEACESAT,
16 November 1993.
The memorandum does not provide specific guidance regarding
the priorities of the program but was intended to raise
issues regarding the effort required to expand services
through creating a digital carrier
network for PEACESAT.
-
There are several reports that describe the technical characteristics
of GOES-3:
Williams, P. & Yaldwyn, J. 1991. "Designing an
Inexpensive and Innovative S-Band Earth Station Network:
The Challenge". Proceeding: Pacific Telecommunications
Conference. Honolulu, Hawaii.
Leary, J. 1993. "Provision of PEACESAT Links Operating
at 64 Kbps to 124 Kbps". MAS Technical Report. Wellington,
New Zealand.
Leary, J. 1993. "Satellite Downlink Level Variations
of GOES-3". MAS Technical Report. Wellington, New Zealand.
-
Okamura, Norman. 1993. "Preliminary Assessment and Conceptual
Design for the Use of the GOES-3 to Provide Improvement Services
in the Pacific". University of Hawaii, Honolulu, Hawaii.