Bearers - International
This section provides a timeline for New Zealand's international bearer systems, these being communications technologies carrying multiple channels of information between New Zealand and other nations. International bearers are the follow-on technology from beam wireless services and had a major impact on the way the NZPO and subsequent owners provided communications services. The 'bearer' name is used to show the services 'bear a large load of information', as opposed to the single or dual channel radio services which have been discussed so far.
In July 1962 the first section of the Commonwealth Pacific (COMPAC) cable linked Australia and New Zealand. By December 1963 the cable service extended to Canada via Fiji and Hawaii. A terrestial microwave bearer carried COMPAC cable traffic across Canada where it connected to the Canada Transatlantic Cable (CANTAT) for onward connection to the UK and Europe. The cable was a lightweight coax which had a 240 kHz bandwidth in each direction to support 80 two-way analogue voice channels, any one of which could instead be used for up to 22 telegraph channels. The COMPAC cable was withdrawn from service in 1984 when it was superceded by the ANZCAN cable.
International voice, telegraph and radiophoto traffic was transferred off beam wireless systems on to the COMPAC cable. However, COMPAC did not spell the end for beam wireless as radio was required to maintain a backup of 50% of the COMPAC services in case of cable failure. Consequently, the Makara/Himatangi Radio combination continued to provide live duplicated COMPAC traffic channels overseas by beam wireless.
In 1966 Australia completed a terestial microwave bearer system up the east coast of their country and in 1967 this service was connected to SEACOM (South East Asia Commonwealth cable) at Cairns for Asian communications services. This link was utilised by New Zealand via its COMPAC cable connection.
Warkworth Satellite Station
In July 1971 the NZPO opened Warkworth Satellite Earth Station to provide telephone and television bearer services via the INTELSAT series of communications satellites. Warkworth telephone channels were connected via a 960 channel microwave bearer to the International Telephone Exchange in Auckland. Warkworth also provided a 'standards converter' to allow US NTSC television pictures to be viewed on New Zealand PAL televisions. Warkworth services were expanded by installing extra satellite dishes in 1984 and 1988. Other satellite earth stations were later installed at Wellington, Rangiora (Christchurch), Chatham Islands and Scott Base, Antarctica.
Warkworth Satellite Station still carries some traffic via small dishes, but over 80% of New Zealand's voice traffic was transferred to SOUTHERN CROSS in 2000. Warkworth's first big dish was dismantled in 2008 and its second big dish was leased to the Auckland University of Technology in 2010 for conversion to a radio telescope.
In 1976 the Australian Overseas Telecommunications Commission and the NZPO installed TASMAN 1, a coaxial cable system providing 480 x 5 kHz voice channels. The cable was withdrawn from service in July 2001 when it was superceded by the SOUTHERN CROSS cable system.
In 1984 the ANZCAN cable replaced the COMPAC cable. It provided 480 two-way voice channels over a 5 MHz bandwidth coaxial cable. The New Zealand section of cable extended to Norfolk Island where it connected with a higher capacity cable having a 1380 channel capacity laid between Australia and Canada. This cable was withdrawn from service in May 2002 when superceded by the SOUTHERN CROSS cable system.
In 1992 Telecom New Zealand installed the TASMAN 2 cable between Sydney and Auckland. TASMAN 2 provided 2 x 560 Mbps digital circuits.
In 1993 AT&T and Telecom New Zealand installed PACRIM EAST between Hawaii and Takapuna. PACRIM EAST provided 2 x 560 Mbps digital circuits.
In 2000 Telecom New Zealand and others installed SOUTHERN CROSS, a fibre optic cable installed as three joined rings offering multi-redundancy. It provides a digital service between Australia, New Zealand, Fiji, Hawaii and the west coast of the United States. Initially providing 240 Gbps across the network, it was upgraded in 2012 and 2013 to achieve 2.7 Tbps and in 2014 to 3.6 Tbps. The network is expected to be able to handle expansion to greater than 12 Tbps. Southern Cross is owned (2015) by Spark (50%), SingTel Optus (40%) and Verizon (10%).
Satellite and cable services provided cheap, high quality international voice circuits and eventually made beam wireless services redundant. Himatangi Radio closed in September 1993 and Makara Radio closed before 1996.