Spring 1991 Status Report of Hubmaster and Intermediate Speed Network Development in Northern California. This is an update of some of the recent moderate speed amateur radio network developments in Northern California already described in the 9th ARRL Computer Networking Conference proceedings, QEX Magazine and elsewhere. As previously stated, our efforts are not only toward providing faster hardware and link layer operation but to more efficiently use amateur radio resources to provide amateurs with network layer access at moderate speeds. We anticipate that this will greatly improve current amateur radio applications and also provide a platform for completely new ones over wide areas. We hope that many "non-digital" amateurs will find the services such a network can provide to be both interesting and personally useful. We also hope that "non-radio" individuals with computer and networking interests will discover amateur radio as a wonderful environment in which to pursue their interests. Doing all this requires new radio hardware and digital hardware to handle the .25 Mbps to approximately 2 Mbps data streams. Economical operation at this performance level requires line-of-sight radio links. Hardware and new protocols which effectively utilize it are being devised. We have developed an architecture which allows small groups of amateurs to share both the expense and performance in a manner similar to current NBFM repeaters. One of the goals of this moderate speed solution is to solve the hidden transmitter problem without requiring users to suffer the additional complexity and expense of full duplex radio hardware. We have found AX.25 not to be sufficient for these goals. Perhaps most importantly, new kinds of coordination and cooperation among amateurs are becoming necessary to successfully implement all of this. System Components At present the intermediate speed radio hardware includes 900 MHz, 256 kbps 10 watt radios along with 13 element yagi antennas and a commercial colinear antenna for use at the hub. See the Hubmaster paper in the 9th ARRL CNC and March 1990 QEX/Gateway for details. Interface hardware to connect the radio(s) to the digital i/o is also necessary. Some of the 256 kbps radios along with the previously described 2 Mbps microwave link hardware may be used on initial backbones. The digital interface, MIO ("Mundane" or "Multi-function" I/O), can plug into a user's personal computer or be run standalone (remotely) as a hubserver and multiport switch/router to the backbone and other clusters. MIO has up to 4 SCC ports capable of driving a great variety of radio or wireline hardware. It is capable of emulating a conventional AX.25 TNC on one port while it serves a 1Mbps microwave backbone connection and a cluster of users running Hubmaster protocol at 256 kbps on other ports. A "stripped down" version of MIO can be run as the interface between the user's computer and 256 kbps radio. In order for all this hardware to operate together considerable software is necessary. This includes a packet driver for KA9Q NOS, Hubmaster primary and secondary software along with a software development toolkit including debugger. Provision has been made so that software can be written in C++ and put into ROM or loaded into RAM either via over-the-air transfer for the remote case or through shared memory to the PC in the plug-in case. The toolkit will provide basic interface to the Hubmaster polling protocol allowing developers to port their own protocols into the environment. If Borland C is used, then S/W debugging can be done via the TD/TDREMOTE interface. Status of Individual Components Radio Hardware, N6GN For several months two 10 watt radios, a prototype and a "pilot" unit, have been complete. A bit error rate tester was designed and built and BER and multipath distortion measurements have been made on-bench as well as across a variety of real paths from 50 feet to 7 miles using the first two radios. A quantity of commercially fabricated printed circuit boards have been made. One radio using the commercial boards is now virtually complete and working. Major parts for building 12-15 units are on hand. The intent is to build approximately 6 more radios for immediate deployment by N6RCE in Hubmaster protocol development and by N6GN for inter-cluster backbone communications. 13 element 5' boomlength yagi antenna have been designed, built and measured. Performance is within a few tenths of a dB of expectations. A commercial omnidirectional colinear for hub use is being evaluated. Interface circuits which provide logic level conversion between the radios and MIO are completed. Additional interfaces with provision for external clock/data encoding and decoding are in progress. Digital Hardware, N6RCE The basic MIO PC card has been completed. Ten boards have been commercially fabricated. Two of these have been loaded and the hardware completely debugged. Software development is proceeding. Additional boards are being assembled. MIO is designed as a full length IBM PC plug-in adapter. The card sports a V40 microprocessor running at 8MHz, 768K DRAM, up to 256K EPROM, and a pair of ZILOG ESCCs. It is designed for 8MHz (ISA) 8-bit slot PC buses but will function in any AT slot. MIO can function in any of three ways; entirely standalone, only drawing power from the PC or it can interface with the host processor. Interface is via a shared memory window. The size can be either 8K or 64K. The shared memory window address and size are set by writing to a control I/O register. Possible base addresses for the window are C8000, CC000, D8000, DC000. This control register also allows the host PC to generate interrupts to the V40, and to program the IRQ line used by MIO to interrupt the host. The V40 is an integrated microcomputer containing an interrupt priortizer, four DMA channels, and three timer/counters. The DRAM refresh controller and external bus arbiter for sharing DRAM with the host PC are also utilized. Software, N6RCE A software toolkit supports development and debugging with Borland C++ V2.0. A complete operating shell is supplied including linking, relocating and loading of code written on a PC platform. A run-time kernel provides for TOD keeping, interrupt management, DMA management, buffering, protocol manipulation and easy access to the Zilog ESCC ( give us your buffer, we'll get it there ). The programmer will be able to write software on a PC platform, compile and link on the PC with Borland TC++, load it onto the adapter, and debug it with the remote debugger supplied with TC++. (TC++ has a facility (TDREMOTE) which allows the target program to be debugged to run on one PC and the debugger to run on another PC. The two debuggers communicate via a serial link). This feature provides the possibility of remotely developing software running on hardware located at distant sites such as Hubmaster hubs or hilltop backbones from the comfort of a home QTH. System Status, Timetable, Targets and Priorities All development is currently being performed and funded by N6RCE and N6GN. Limited personal resources have set the speed of progress. We hope as hardware and protocols come on-line in Northern California that others will step in to develop applications. Such applications are becoming increasingly important to the furtherance of the project. We also hope that hardware will become commercially available for use by others outside of Northern California to start developing and enjoying the benefits of higher speed user network access. Current emphasis is on getting a minimal hub and backbone operating in time for the next ARRL Computer Networking Conference at San Jose, CA in September. Deployment of one or two clusters along with an interconnecting 256 kbps backbone is planned. To accomplish this, Hubmaster protocol refinement and backbone hardware/software development are running in parallel at N6RCE and N6GN, respectively. Future Targets and Checkpoints Future directions all rest on the completion of a functioning hub and backbone. Once this is accomplished the number and variety of options is very large indeed. Additional radios on other 900 MHz and 1200 MHz channels will need to be deployed to allow multiple physically close clusters to coexist. N6GN anticipates first modifying 900 MHz radios for 1200 MHz operation and then building all future radios in the 1200 MHz band. A minimum-expense combination low power user radio/interface ("layer 3 tnc") is anticipated with the goal of further reducing the cost of user hardware. N6GN hopes to have an opportunity to apply some ideas to substantially improve the cost/performance of microwave backbone hardware. In Northern California we hope to add additional clusters and to extend the backbone so that the Bay Area, Santa Rosa, North Coast and Sacramento users all have higher performance connectivity. Clearly these directions and opportunities require the cooperation and efforts of many people with many different talents. We hope that as others see functioning hardware and protocols along with available development tools that they will join in building and extending the network both in expanse and services. Since the function of the network is to support new and improved amateur radio applications we hope that many new ones will emerge. Existing BBS traffic and possibly DXPSN traffic may be supported. We hope that wider area connectivity will evolve. The SF Bay Area to Southern California path is one early possibility. NNTP, "News" protocol, client and servers are already in use at lower speeds and this network should be much more able to support Usenet style distribution of dialogue and information to amateurs over a wide area. Many other applications including amateur FAX, voice mail, digital voice and a NBFM to IP gateway, to name a few, are being considered. Where to Find Out More Since this is just an update on our recent intermediate speed networking efforts we refer you to December 1989 Ham Radio Magazine, the 1991 ARRL Radio Amateurs Handbook, March 1990 QEX/Gateway and particularly to papers in the 8th and 9th ARRL Computer Networking Conference proceedings for details of our approach and what we are doing. de N6GN and N6RCE April 9, 1991