Ungermann-Bass Inc and Hewlett-Packard Co have teamed again, this time to develop interoperable products that support 10Mbit-per- second IEEE 802.3 Ethernet transmission over low-cost telephone wiring. Each will continue to develop its own products but will share techno-logies to ensure that the products are interoperable over high-speed unshielded twisted-pairs, offering the performance of Ethernet without the expense of new cabling. The technology also offers the flexibility of running Token-Ring, Ethernet or a combination without rewiring. Ungermann-Bass resolves interference problems by using advanced filtering and signal conditioning techniques and a two-pair balanced transmission system. with technology developed by Hewlett’s research lab at the physical level. The Ungermann-Bass system is des-igned to support connections up to 330 feet from the wiring hub. The Ungermann-Bass and Hewlett-Packard solutions support an Attachment Unit Interface-compatible connector, the Ethernet transceiver cable connection standard so that a wide variety of devices can be attached, in claimed contrast to the use of BNC connectors with thin coaxial, or cheapernet cable. Hewlett’s aim is that its 10 Mbps twisted-pair HP StarLAN 10 should be integrated with other industry standard twisted-pair networks in their company. The agreement one of several co-op-erative pacts between the two: in June 1986 they signed a joint support agreement under which they jointly design, install and maintain broadband local-area cable systems and terminal connection networks. The companies have also signed a letter of intent for the joint marketing of MAP products.
