Spring 2006 Issue

HSMM

The Hinternet and openHSMM
Plus Experiments on 6 Meters

 By John Champa, K8OCL

The term “openHSMM” is derived from the combination of Open Source software and High Speed MultiMedia. Open Source software was designed to meet some of the goals of the ARRL’s High Speed MultiMedia (HSMM) Working Group, chaired by John Champa, K8OCL. The intent of the working group is to research and implement new technologies in high-speed digital signaling networks.

Design Criterion

The openHSMM-ap design criterion is to create a wireless-access-point appliance that contains features found in wireless access points that are commonplace today. Why re-invent the wheel? Today’s consumer-grade access points lack two very important features that are necessary to create flexible wireless networks.

First, the deficiency lies in the radios. Consumer-grade access points traditionally have relied on a single radio to provide connectivity. While efficient in their design, they cannot provide the diverse connectivity options that may be required, especially in an unplanned environment such as those found during emergency communication deployments. Sometimes 802.11b works well, but it would be good to provide alternatives, such as 802.11a or 900-MHz WiFi for creation of backbones. This is one area that openHSMM hopes to address in the coming months.

The second deficiency is the lack of true networking protocols. In order to create a scalable network (wired or wireless), it would be beneficial to provide configuration options such as OSPF (Open Shortest Path First). OSPF is a tried-and-true routing protocol that broadcasts its routes to its neighbors. This is a good fit for HSMM EmComm networks, which are created on an ad-hoc basis, and would allow for dynamic routing configuration as new nodes are brought online, or as some become unavailable.

Opportunities and Challenges
As an amateur radio operator operating under FCC Part 97, we have the benefit of experimenting with different RF technologies and being able to utilize higher power devices than folks deploying devices that adhere to FCC Part 15 regulations. What this means to us is that we can choose from a wide variety of radio spectrum (50 MHz, 900 MHz, 1.2 GHz, 2.4 GHz, and 5.8 GHz, etc.) and deploy those devices with amplifiers or high-gain antennas and create long-distance network links that cannot be achieved under Part 15.

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