Introduction

Oxford Falls ITC was initially established by OTC (the Overseas Telecommunications Corporation) as a satellite earth station in 1987 at a then estimated cost of $26m. It provided access to the Intelsat Pacific Ocean Region geostationary satellites from a location as close as possible to the international gateways at Paddington and Broadway, and to major Sydney based customers.

It began with only one antenna providing FDM (Frequency Division Multiplexing ) and TV services and has now grown to include a 40,000 line international telephone exchange, a satellite Teleport area currently consisting of 2 antennae, four Intelsat Standard A antennae (one for each of the Intelsat Pacific Ocean Region satellites at 174, 177, 180 & 183 Deg E), and serves as a termination point for the PacRimWest undersea optical fibre cable system. The estimated value of the facility, in 1998, is over $100m.

Background

In the mid-1960’s, with the advent of international telecommunications via geostationary satellites, Australia's first satellite earth station was built at Carnarvon in Western Australia. Its role was to provide communications for the NASA Manned Space Program between NASA and the NASA Tracking Station located in Carnarvon.

Soon after, a site was sought on the east coast for an earth station to carry commercial telecommunications traffic. The radio frequency licensing conditions applying at that time required that satellite earth stations be located at sites considered acceptably free from RF interference in regards to both satellite links and terrestrial radio links. A site satisfying these requirements was found near Moree in northern NSW and the Moree 1 antenna was established to work the Primary Path satellite.

During the 1970’s, several investigations were undertaken to find a site for an earth station closer to Sydney in order to avoid the relatively high costs associated with the operation of a remote site such as terrestrial tail rental, staff housing, and energy and maintenance costs as well as permitting a greater flexibility in delivery of new services to customers. However, the need to be free from interference to and from terrestrial radio systems and the lack of comprehensive data about interference mechanisms at that time, meant a suitable Sydney site was not identified.

Thus when OTC needed to work the spare spacecraft for the ABC Remote Area Television Services, a second antenna system was established at Moree. Better radio frequency usage co-ordination was subsequently made possible by improved interference prediction techniques so that in 1982, after commercial interests were permitted to establish receive-only international earth stations in Australia, suitable sites for OTC earth stations near Sydney, Melbourne and Perth were pursued. Several areas around Sydney were identified as being relatively free from rain scatter interference and various sites with good terrain shielding were tested for great circle interference from existing terrestrial radio links.

The area to the north east of Sydney beyond Frenchs Forest had the additional advantages of good access and availability of services and, following negotiations, the site at Oxford Falls was eventually acquired.

Site

Oxford Falls ITC is located to the north of Frenchs Forest in a valley between Oxford and Snake Creeks. The site fronts onto Oxford Falls Road West and is accessible from either Wakehurst Parkway via Oxford Falls Road West or from Forest Way via Morgan Road. Oxford Falls is approximately 17 km north of the Sydney CBD and is one of the last remaining rural pockets within the Warringah Shire.

The earth station compound occupies about 5 acres out of a total of 25 acres. The majority of the remaining land has been grassed and landscaped. A radio repeater site is located off Perentie Road, Belrose and is connected to the facility by optical fibre cables.

Geographical Location

The geographical location of Oxford Falls ITC is as follows :

Latitude 33 deg 43 min 38 sec South

Longitude 151 deg 13 min 48 sec East

Implementation

The construction of Oxford Falls ITC (or Sydney Satellite Earth Station as it was then known) was initiated in 1984 with ministerial approval for acquisition of the site, followed by submissions to and agreements with various authorities including Warringah Shire Council.

Major building works commenced in December 1985 with the bridge over Oxford Creek and were completed with the station building by June 1987 . The first major antenna system (an 18 metre Intelsat Standard ‘A’) was completed and placed into service in October 1987.

This was followed by the relocation of the second major antenna from Moree (a 32 metre Intelsat Standard ‘A’) which was ready for service in June 1988. Whilst this 32 metre Sydney 2 antenna was being installed and commissioned, a temporary antenna, a 7.3 metre Intelsat Standard ‘F2’, was available in November 1987 for the implementation of Intelsat Business Services (IBS) and public digital services (IDR).

Another 18 metre Intelsat Standard ‘A’ was installed by November 1988 and a fourth antenna (again an 18 metre Intelsat Standard ‘A’) was relocated to Sydney from OTC’s site at Healesville near Melbourne. TV traffic was transferred to this in September 1992.

There are two other antennas in use at Oxford Falls ITC. These ‘F3’ antennas are in what is known as the Teleport area and are both 9 metres in diameter. One points at AsiaSat2, located at 101.5 Deg E and the other points to PanAmSat2 which is located at 169 Deg E. They were ready for service by mid-1996.

Building expansion work to accommodate the PacRimWest cable system was completed by February 1993 with installation of equipment, cable trays etc..

”Live” traffic was placed on the cable as of February 1995. The Alcatel S12 International telephone exchange with accompanying transmission equipment was fully operational by November 1996.

Power

The electrical power feed for the facility is from Sydney County Council at 11 kV through an on-site 11kV/415V substation currently rated at 1500 kVA and capable of expansion to 2000 kVA. Should there be a break in the SCC power feed, there are two autostart diesel generators (continuously rated at 1500 kVA) provided as backup to the mains supply. One Diesel Generator Set can supply the total load of the station.

A third diesel generator (continuously rated at 500 kVA) is also available but, under normal circumstances, is only intended for use during UPS system maintenance.

As well as automatically restoring power to the Main Switchboards, Diesel Generator Sets 1 and 2 can be manually connected/disconnected from the Main Switchboards without break by paralleling for a short period during the transition.

Diesel Generator Set 3 can also be manually connected/disconnected to the Main Switchboards but a five (5) second break of power occurs each time and it is not automatically connected.

Oxford Falls ITC Facts

Satellite Earth Station Antennae

Sydney 1A is primarily used for the restoration of satellite and cable services. It is also used for antenna restoration if required. For example, should Syd-3A develop a tracking problem there is the capability to restore the services currently on Syd-3A via Syd-1A by pointing Syd-1A to the correct satellite (180 Deg E) and performing some patching.

Sydney 2A is used for many services such as IBS, IDR, SCPC, DAMA as well as itinerant TV services.

Sydney 3A is primarily used Leased TV services, especially to TVNZ.

Sydney 4A is also used for transmission and reception of IBS and IDR services, as well as itinerant TV services.

S12 International Telephone Exchange

Manufacturer : ALCATEL

This international exchange has a capacity to simultaneously switch 40,000 phone/data calls. While the S12 Exchange is located at Oxford Falls ITC, it is administered and maintained by Telstra staff from Paddington terminal.

PacRimWest Cable Station

Manufacturer : ALCATEL

The Pacific Rim submarine cable system provides telecommunications across the Pacific Ocean Region. There are many optical fibre cables involved and one of those is the PacRimWest cable which is located between Oxford Falls ITC and Tumon Bay in Guam. It arrives on Australia’s shore at Narrabeen Beach where it then travels underground for approximately 11 km, crossing five suburbs before terminating in the Oxford Falls ITC PRW Cable Station.

The cable consists of 4 individual optical fibres, each with a capacity of 565Mbits. Two of the fibres are used as the primary working pair with the other two fibres used as a backup should a fault occur with the primary pair. As Oxford Falls ITC is a termination point for this cable, the facility includes a cable station section which houses the necessary equipment involved in cable telecommunications.

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