Vendors announce 1 ¥ 9 transceiver alliance
By robert pease
Seven fiber-optic component suppliers have signed a multisourcing agreement (msa) for 1 ¥ 9 duplex, 5-V-form-factor Gigabit Ethernet transceivers that will share a common footprint. The transceivers also will feature a common termination, biasing, and signal-detect interface.
The group includes Sumitomo Electric Lightwave Corp. (Research Triangle Park, NC), Siemens Microelectronics Inc. (Cupertino, CA), Optical Communications Products Inc. (Chatsworth, CA), Molex Fiber Optics Inc. (Lisle, IL), Honeywell`s MicroSwitch Division (Minneapolis, MN), Hewlett-Packard Co. (Palo Alto, CA), and amp Inc. (Harrisburg, PA).
The agreement gives customers a choice of vendors for 1 ¥ 9 Gigabit Ethernet transceivers that meet the same termination criteria. While a 1 ¥ 9 transceiver footprint with a standard termination was already well established within the industry, board manufacturers began to demand specialized footprints and termination schemes when they moved to high-speed products, mainly because the chipsets being used sometimes were not all based on positive emitter coupled logic (pecl) interfaces. Transceiver manufacturers, attempting to hit a moving target, began to offer a wide variety of transceiver packages. Thus, prior to the msa, customers had to review their pinning requirements and the chipset being used before sifting through a potentially bewildering variety of transceiver options.
Now, the companies involved in the msa will each produce a 1 ¥ 9 transceiver with a common package footprint and pin definitions. The transmitter and receiver pins will use identical DC-coupled electrical interfaces, which will require electrical biasing and termination to be done external to the transceiver on the customer`s printed circuit board. The signal-detect pin will employ a pecl interface. The hope is that the msa will spur board manufacturers to adopt common designs that will take advantage of the new transceiver packaging.
This announcement comes on the heels of a previous msa in which six manufacturers agreed to redesign their trans ceivers to the new small-form factor specifications that are roughly half the size of previous offerings (see Lightwave, April 1998, page 1). This latest agreement takes what the seven vendors consider to be the next logical step to transceiver standardization.
Says one member of the group, however, this step should have been taken much sooner. Jay Garcia, from Hewlett-Packard`s Fiber Optic Business Unit, believes there would be a dramatic decrease in the number of different transceivers on the market today if the msa had been achieved a year ago. "If we could have wrapped up this agreement earlier," says Garcia, "we would have done ourselves and our customers a favor by eliminating the need for incorporating multiple termination schemes into our products."
The most obvious advantage of the msa is for the customer. With many vendors to choose from, all offering the same footprint, customers can build boards with a single kit of parts. Cost is also an advantage, with prices being driven down by the newer small-form-factor devices. The vendors will benefit by having to stock fewer specialized transceivers.
Currently, there are many different termination schemes available, such as AC-coupled, DC-coupled, and combinations of AC and DC. Most tran sceiver manufacturers incorporate into their products the ability to interface with several schemes. The msa footprint should alleviate this need to some extent. However, says Garcia, there will always be customers who believe that an alternative configuration is better for their chassis, so vendors will continue to produce hybrid systems to satisfy their customers. "In essence, we must remain flexible while our customers can actually standardize to some extent," says Garcia.
Transceivers are used primarily to interface with networks or backbones. Units with higher data rates are used in backbone applications, while transceivers for lower data rates are in fiber-to-the-desk applications. The new msa does not cover the connector that provides this network interface, which thus remains the option of the customer. "After a lot of what we call the `connector wars,` some standards bodies have decided not to choose a particular connector," says Schelto van Doorn, an engineering manager in Siemen`s fiber optics unit. "They believe the market will eventually drive the final decision." (See Lightwave, May 1998, page 44 for more information on the controversy surrounding standards for small-form connectors.)
There is no shortage of organizations willing to help the market reach that decision. For example, the "mt-rj Alliance"--which comprises amp, Hewlett-Packard, Siecor, USConec, and Fujikura Ltd.--is seeking support for mt-rj as the industry standard. Supporters include the newest convert, Bay Networks Inc., as well as Cisco Systems Inc., Cabletron Systems, xlnt, and Transition Networks Inc. Other available connector options include, but are not limited to, Lucent Technology`s LC connector, 3M Corp.`s VF-45 (the choice of the Fibre Channel Association and commonly called the SG by standards bodies), and ibm-Siecor`s sc/dc optical connector. q