By Kris I. Mraz, N5KM High Speed Multimedia Radio Data, voice and video––simultaneously! Experiments are demonstrating the feasibility of low cost, low power technology for the new ham radio “Hinternet.”

High Speed Multimedia (HSMM) consists of a low power microwave trans- A small built-in antenna is used on the Radio ceiver that uses a form of spread spectrum desktop PC or laptop so it can communi- HSMM radio is based on what is com- (SS) modulation. Spread spectrum modu- cate with the AP . Devices using the mercially known as Radio Local Area Net- lation is a way to spread modulation fre- IEEE 802.11b standard (known as WiFi work (RLAN) Technology.1 Take a look at quencies over a very wide signal bandwidth commercially) use frequencies in the 2.4 Figure 1. Each PC (desktop or laptop or while at the same time reducing the power GHz range. That standard must be robust palmtop) has an inexpensive (less than transmitted at any specific frequency. The enough to handle the uncertainties of the $100) radio transceiver/antenna unit at- SS transceivers most studied are manu- radio medium as well as deal with prob- tached to it. Radio repeaters, called nodes factured under a standard called IEEE lems that a wired LAN has never heard of. and known commercially as Access Points 802.11b and the signal occupies a band- Therefore, we’re looking at the marriage (APs), are scattered around the home or width of 22 MHz (11 MHz either side of of radio and software technologies in a office to receive their radio signals. the channel’s center frequency). leading-edge advancement of networking. Now those PCs are no longer tied down. They are free to roam the local area, untethered by an access cable. And, Wired Local Area Network like your cell phone, as you roam around Wired Link the city, your signal can be lost by one Access Point Access Point node but picked up by the next––you’re always connected. Just don’t roam too far. Radio Link These RLAN radios, with their little an- tennas and QRP transceivers, aren’t made for weak-signal work, though. Their in- door range is typically less than 200 feet! The Technologies

What are the technologies that allow PC Laptop Palmtop RLANs to work? The radio component Figure 1––Radio Local Area Network. Devices such as PCs, laptop and palmtop 1Notes appear on page 34. computers are connected to a LAN via microwave.

Access Point Access Point

Radio Link

Ham 1 Ham 2 Ham 3

Figure 2––Part 15 microwave radios can be adapted to establish communications among many hams over a large area. From April 2003 QST © ARRL What Does all this Have to do with ? Table 1 IEEE 802.11b Spread Spectrum Channel Assignments for the IEEE 802.11b transceivers, sometimes 2400-2483.5 MHz Band called WiFi devices, actually operate through the range of the 13 cm amateur Channel Center Freq, MHz Comments band and beyond. How can they operate 1 2412 Channels 1-6 are used in the US and other countries by 802.11b devices. Their emissions fall in the ham bands? All of these wireless within the 2400-2450 MHz amateur band. devices operate under FCC Part 15 rules. 2 2417 This means they are unlicensed users of 3 2422 the band and, as such, they must not cause 4 2427 interference to licensed users (hams) and 5 2432 must accept any interference caused 6 2437 them. That is the way the FCC handles 7 2442 Channels 7-11 are used in the US and other Part 15 band sharing among the various countries by 802.11b devices, but cannot be services. Hams can take advantage of the used in the Amateur Service. availability of low-cost Part 15 IEEE 8 2447 802.11b hardware by applying it to our 9 2452 Part 97 service. Imagine your own Part 10 2457 97 wireless network running high (rela- 11 2462 tive) power with high gain antennas tied 12 2467 For use in Europe only. together in a nationwide network. 13 2472 For use in Europe only. Figure 2 takes the same technology 14 2484 For use in Japan only. illustrated in Figure 1 and shows how many amateurs over a wide area are able to communicate via data, voice and video. Since the 9/11 tragedy, Amateur cell phones work––and we generally pre- Veteran hams will recall that the adapta- Radio has taken on a heightened role in fer it. RLAN technology allows for full- tion of commercial FM equipment to the national, regional and local area emer- duplex operation in voice, video and data 2 meter band enabled FM repeaters to gency communications. Emergency com- communication modes. proliferate in the 1970s. munication organizations like RACES and ARES are establishing emergency Voice over IP (VoIP) Applications response plans with government organi- VoIP applications such as eQSO, What if you had the ability to build zations such as the National Commu- iLink, EchoLink, IRLP and WIRES are networks like these? What would you do nication System (NCS) and the Federal all practical operations using the HSMM with them? Well, one of the exciting char- Emergency Management Agency mode.2 Explore and let your imagination acteristics these networks share is their (FEMA). Along with traditional commu- go to work in these areas! high capacity. This means nication channels, such as HF/VHF nets, they have the ability to move lots of data and APRS, wireless LANs Digital Voice from one point to another with high reli- need to become an integral part of the Digital voice lets us use RLAN tech- ability. RLAN technology also allows a Amateur Radio response. nology to add exciting new capabilities single data source to send to a single re- to the old DX PacketCluster operation. ceiver or to many receivers using multi- Two-Way Streaming Video (ATV) Formerly, we just used a terminal pro- cast technologies. Imagine a local Amateur Radio gram to enter DX information and re- Aside from expected -type videophone network that can be operated trieve WWV reports or we chatted by usage—e-mail, Web browsing, FTP, IRC from a PC, but with an RLAN communi- keyboard with other amateurs on the net- (chat) and Instant Messaging—many po- cations medium. Each station can use a work. Now we can take advantage of a tential applications could be built with simple webcam attached to a PC and that widespread, high-speed network with this technology. PC can be connected to the network via a wireless connectivity and enhance these simple wireless access device. Such a capabilities to make them more interest- Emergency Communications network would support both point-to- ing and effective. Instead of just seeing a Emergency communications offer the point and multipoint video calls. DX item, we could click on that spot and greatest opportunity for RLAN technol- hear the actual sound of the DX signal at ogy to excel and for amateurs to push the Full Duplex Streaming Audio the spotter’s location. We could also turn envelope in the public service sector, Imagine never having to say “over” to that “talk” function into a real two-way using the technology. Low power require- transfer transmission. One of the great voice communication tool. ments, low cost, portability, point- barriers to truly conversational contacts to-point, point-to-multipoint and multicast has always been the simplex communi- Remote Control capabilities, coupled with high bandwidth, cation modes we traditionally use. Ever think about putting your station make RLANs an excellent technology for Whether it’s SSB, CW, AM, FM, RTTY in a perfect, uncompromised location “on-the-spot” emergency communica- or advanced digital, other than talking and operating from the comfort of your tions. An emergency volunteer can be over the OSCAR satellites, we typically home? Well, an RLAN approach could equipped with a laptop or a wireless PDA wait for the other operator to finish a be the solution, with the right capa- (Personal Digital Assistant) with a micro- transmission and then commence send- bilities at the right price. With a single phone and a small video camera. He or ing. Full-duplex operation is the ability link from your home to a remote site, she now has the tools needed to act as a for all parties in a contact to be able to you could run full-duplex audio and mobile set of eyes and ears in the midst talk to and hear all other parties simulta- integrated control of your distant of a communications emergency. neously. That is how our telephones and station. From April 2003 QST © ARRL Table 2 Antennas for the Hinternet ARRL 13 cm Band Plan (2400-2450 MHz) By Neil Sablatzky, K8IT Band, MHz Amateur Usage In order to minimize 2400-2403 Satellite interference to FCC Part 2403-2408 Satellite high-rate data 15 users, the ARRL HSMM 2408-2410 Satellite Working Group recom- 2410-2413 FM repeaters (25 kHz mends the strict use of spacing) output horizontal polarization. 2413-2418 High-rate data This is because the major- 2418-2430 Fast-scan TV ity of Part 15 users are 2430-2438 Satellite vertically polarized. It is 2433-2438 Satellite high-rate data important to note, how- Figure A—The design of the slot antenna allows it 2438-2450 Wideband FM, FSTV, ever, that the wireless to be easily reproduced with a milling machine. FMTV, SS, experimental industry uses diversity antennas to achieve both space and polarization diversity. Space diversity is used to reduce the effects of reflections and RF nulling. Wireless Internet Polarization diversity is used to maxi- This is the one application that has mize signal strength when portable caused the most excitement in the Part 15 devices such as laptop computers are positioned without respect to the wireless community. Non-profit Part 15 receiving Access Point’s polarization. user groups have sprung up in the Bos- For amateur use, the majority of our ton, Seattle, San Diego, the San Francisco links will be at greater distances than Bay areas and in many other parts of the those in an office environment. In fact, world. While community-based network- our goal is to be able to network over ing may seem like the latest and greatest many miles of separation. In this thing, hams have already been there. In case, using a common polarization the mid-1980s through the ’90s, amateurs with high gain antennas will maximize used a TCP/IP protocol implementation that communication distance. called Network (NOS) There is an issue, however. In a network, you want each station to written by , KA9Q, to intercon- hear all other stations in the same nect packet radio with the Internet, creat- RLAN. This calls for omnidirectional, ing what was then called the AMPRnet. as opposed to directional, antennas. Now, with commodity-priced RLAN cards You say omnidirectional, horizontally and the additional privileges that Part 97 polarized, high gain antennas? Yes! conveys, we should be able to attract Part Thanks to Trevor Marshall, 15 enthusiasts to the Amateur Service. www.TrevorMarshall.com/, such an antenna (a slot array) is not only The Bands possible, but is relatively easy to The FCC has authorized spread build. The K8IT version of a 32 slot, 15 dBi gain antenna is shown being spectrum devices on three bands: 902- machined in Figure A. Two completed 928 MHz, 2400-2483.5 MHz, and 5725- antenna prototypes can be seen in 5850 MHz. US hams have spectrum in all Figure B. The antenna provides an three of these bands: 902-928 MHz, 2400- omnidirectional radiation pattern with 2450 MHz and 5650-5925 MHz. For the most of its RF energy aimed at the time being, we’ll limit our discussion to horizon. Additional information about the 2.4 GHz band. This is where most com- this slot antenna design can be ob- 1 mercial low-cost hardware is available and tained at K8IT’s Web site. where most of the activity is taking place. Some commercial manufacturers such as M2 Antennas2 and ICOM3 Let’s take a look at how Part 15 de- have recently announced a desire to vices use the 13 cm band. Table 1 shows enter the Amateur Radio market with that the band is divided into 14 channels products compatible with the spaced 5 MHz apart. The US and Canada Hinternet. Please contact these are limited to channels 1-11 while Eu- manufacturers directly for product rope and Japan have different assign- information. ments. The spread spectrum signal is spread ±11 MHz around the channel cen- 1An assembled Amateur Radio version of ter frequency. So in order to prevent co- the slot antenna can be obtained from K8IT at www.k8it.com/. channel interference two networks can be 2www.m2inc.com/. on channels that are separated by 5 chan- 3www.icomamerica.com/wlan. nels. For instance, channel 1 and chan- nel 6 would provide adequate separation. Channels 1 and 6 fall completely Figure B––Two freshly machined prototype slot within the amateur band 2400-2450 MHz antennas ready for finishing. and could be used by amateurs under Part From April 2003 QST © ARRL 97 of the FCC Rules permitting spread however, the Amateur Service has a sec- are available for commercial installations spectrum operation. However, Channel 1 ondary allocation in the 2400-2402 MHz but these can be quite expensive. Some high power spread spectrum operations segment, a primary at 2402-2417 MHz amateur antenna manufacturers are by hams could cause interference with and a secondary at 2417-2450 MHz. This getting up to speed, however, and they other hams operating weak signal and band (actually a larger band of 2400- should soon have products for the amateur narrow bandwidth modes, so it should be 2483.5 MHz) is used by a number of market. Additionally, homebrew antennas avoided by Part 97 users. Hams should unlicensed low-power devices, such as are a possibility, if you feel comfortable try to confine their IEEE 802.11b spread cordless telephones and radio local area using simple machine tools. (See the spectrum use to channel 5 (2432 MHz), networks. These include IEEE 802.11b Antennas for the Hinternet sidebar for whenever possible, as this offers the least devices. The trade press and some manu- information on the construction of a high chance of interference with narrowband facturers often mischaracterize this band gain amateur antenna.) users. We will cover more of this later. as “unlicensed spectrum,” which may There are other occupants in this band indicate they’re either unaware of the Comparison of Part 15 and aside from wireless LAN users. This is amateur primary or secondary allocations Part 97 Rules known as the Industrial, Scientific and or they don’t want to alarm potential cus- Amateurs operating spread spectrum Medical (ISM) band operating under Part tomers. Additionally, the FCC, on peti- are permitted many times the power of 18 rules. Basically ISM is unlicensed, non- tion from the ARRL, issued a Notice of unlicensed Part 15 stations. Hams can run communication use of the band for such Proposed Rule Making, proposing an up to 1 W of transmitter power output things as Magnetic Resonance Imaging upgrade of the 2400-2402 MHz alloca- without so-called automatic power (MRI), diathermy machines and micro- tion to amateur primary status. control (APC) and up to 100 W if APC is wave ovens, to name but a few. On this used.3 Part 15 users are limited to 1 W, band, ISM rules… other users have to ac- Off-the-Shelf Equipment however, with typical wireless Radio cept whatever interference they get from IEEE 802.11b presents the Amateur Interface Cards running much less than ISM. Being an amateur band, however, Radio community with an opportunity this––on the order of 30-200 mW. there are ham occupants there that we need to use the inexpensive Radio Interface Amateurs also have more freedom in to be aware of. Table 2 shows the (1991) Cards (RIC) for high-speed multimedia antenna selection––we can use whatever ARRL Band Plan for the 2400-2450 MHz applications including streaming video. antennas we want. Unlicensed Part 15 us- portion of the 13 cm band. The IEEE While most prices presently hover around ers are limited as to what antenna types 802.11b protocol did not exist when the $100, some are available at about half may be attached to their wireless devices, ARRL Band Plan was structured. that price. Although the APs are more however. In general, built-in antennas can’t The Amateur Service has an allocation expensive by virtue of lower sales be removed or replaced. Transmit power in the 13 cm band that differs somewhat volumes, they are available for under must be reduced if a replaceable antenna in various countries. In the , $200. External antennas with higher gain is replaced with a higher gain antenna.

Using APRS to Locate Amateur HSMM (IEEE 802.11b) Stations By Jeff King, WB8WKA Some readers may be familiar with the use of APRS (Automatic Position Reporting System) in tracking mobile stations, but APRS can also be used to announce the location and parameters of amateur IEEE 802.11b stations. The APRS community has provided a symbol for the use of amateur IEEE 802.11b stations. It is the black gateway icon with the symbol:  8. Amateurs can beacon their position using packet radio on the APRS frequency of 144.39 MHz. One can use a simple TNC with the beacon text listing the latitude and longitude in APRS format or use one of the many APRS display programs. More info on APRS can be found at Wes Johnston, KD4RDB’s Web site at wes.johnston.net/aprs/. Jim Jefferson, KBØTHN, has adapted his Web site www.aprsworld.net/ to help hams locate amateur IEEE 802.11b stations even if they are not on APRS. Jim’s loca- tor can be found at db.aprsworld.net/datamart/wifi- search.php/. Simply click the search button to find all stations using the IEEE 802.11b standard.

Figure ––APRS map showing the location of IEEE 802.11b stations, K8IT and K8OCL.

From April 2003 QST © ARRL An amateur station using IEEE transmit it as data over a wireless con- before transmitting. If interference from 802.11b must identify periodically, nection, either. Additionally, Part 15 de- Part 15 devices is present, the amateur according to Part 97. Some experimenters vices may share certain frequencies of might be able to seek investigative and have considered modification to the IEEE operation with the Amateur Service. Us- enforcement action from the FCC. 802.11b protocol to map station call signs ers of these devices have a responsibility On the other hand, that Part 15 user into frames in a manner similar to that for mitigating interference to licensed just paid about $100 or so for an RLAN used in AX.25. The simplest way, at least Part 97 users. And, of course, Part 97 card and expects it to operate. He or she for now, is to identify in the text of the users cannot use this spectrum for any may not be happy that it doesn’t work or message, so that anyone with a normal commercial or business use, in compli- that it operates more slowly than expected IEEE 802.11b card can read the identities ance with FCC regulation. because of interference. They could of the stations transmitting. become convinced that the cause of the As we all know, information privacy Interference Factors problem is an amateur station. is a major concern in the public Internet. While the Amateur Service has pri- Unfortunately, there are many more Strong data encryption is used to protect mary and secondary allocations in the Part 15 users than there are Part 97 users. sensitive personal information. For Part 2400-2450 MHz band and Part 15 devices A large number of complaints directed at 15 networks this is not a problem. Hams operate there without a license and must the FCC from commercial users could are not allowed to encrypt, however. This not interfere with or claim protection pose a problem and that outcome might is a situation we’re all used to and it from licensed services, there are difficul- not be “advantageous” for the Amateur should not be a problem. Just as you ties. The amateur licensee looks at the Service. While we may have the legal wouldn’t transmit your credit card regulatory status and surmises there is no right to complain about interference due number over the air, you wouldn’t need to take Part 15 devices into account to Part 15 operations, it is friendlier and more prudent to try to coexist. How many of those experimenting Part 15 folks Glossary would enjoy becoming hams? Reach out when you can. It would be far more Access Point (AP)––A low power repeater or node, usually used to facilitate a wireless link (from a RIC) to a wired network. In our application it can also be a advisable to consider mitigation of any node to link to another wireless AP via radio. interference to and from Part 15 RLANs Automatic Power Control (APC)––A method to use only as much power as neces- in an amateur network rather than sary to access a distant receiving site. Transmitter power is automatically scaled becoming confrontational or litigious. up or down depending on the signal level at the receiving site. Amateur-to-amateur interference is an- FCC Part 15––Part 15 of Title 47 of the FCC rules that regulates low power, unli- other matter with which we must concern censed devices. This equipment may share certain frequencies of operation with ourselves. The requirement to avoid harm- the Amateur Service and, as such, all services are vulnerable to interference from ful interference from spread spectrum op- each other on these frequencies. Part 15 outlines, among other things, certain responsibilities of these services with regard to that possible interference. eration is in the rules––Section 97.311(b) FCC Part 97––Part 97 of Title 47 of the FCC rules regulates and governs the Ama- says that SS stations must not cause inter- teur Radio Service. The governmental rules under which the Amateur Radio ference to stations using other authorized Service exists. emissions. Comparison of Table 1 with Hinternet––HSMM + Internet. Table 2 reveals that it is not possible to HSMM––High speed multi-media radio communication. A term coined for very fast pick an IEEE 802.11b channel within the bilateral data rates usually using the IEEE 802.11b standard over an Amateur 1 to 6 range without bumping into another Service radio network. use specified in the band plan. Bear in IEEE 802.11b––The IEEE 802.11 specifications are wireless standards that specify an “over-the-air” interface between a wireless client and a base station or access mind, however, that there may be some point, as well as among wireless clients. 802.11b applies to wireless LANS and local variations. While it is good practice provides 11 Mbps transmission (with a fallback to 5.5, 2 and 1 Mbps) in the to operate within the applicable band plan, 2.4 GHz band. 802.11b uses only DSSS (Direct Sequence Spread Spectrum) some flexibility does exist. Generally, an modulation. 802.11b is an IEEE copyrighted trademark. amateur station operating in accordance Radio Interface Card (RIC)––A PC wireless transceiver capable of interfacing to a with a band plan has some precedence over wireless network. These usually run between 30-200 mW of RF output power. a station not operating under one. The im- Radio Local Area Network (RLAN)––A communications system facilitating two-way portant issue is to avoid harmful interfer- data transmission among clients and APs using network protocols via radio links. Spread Spectrum (SS)––A digital modulation technique whereby the modulation ence to users operating in accordance with sidebands are spread over many frequencies. In the 2.4 GHz band, the modula- that agreement. The ARRL Repeater Di- tion bandwidth is typically 22 MHz. A pseudo-random code at several times the rectory lists some, but not all, users of the information data rate usually modulates the carrier. Because of frequency inter- band. The local repeater coordinator leaving effects and a much lower spectral power density, SS signals are less should have additional information about prone to interference than conventionally modulated signals. Direct Sequence who is doing what in order to avoid inter- Spread Spectrum (DSSS) is the coding and modulation scheme used by the IEEE ference to existing users. 802.11b standard. There’s also the potential for inter- TCP/IP––A set of protocols developed to allow cooperating computers to share resources across a network. network interference between co-located VoIP––Voice over Internet Protocol. A protocol designed to allow voice transmis- RLANs. Networks typically select sion using high speed two-way data transmission over a network, principally the channels separated by 25 MHz (for Internet. (See S. Ford, WB8IMY, “VoIP and Amateur Radio,” QST, Feb 2003, pp instance, channel 1 and channel 6) so that 44-47, to learn more about the VoIP networks currently implemented in Amateur the “sidebands” from an adjacent channel Radio.) are down at least 30 dB from its center WiFi––Wireless Fidelity (WiFi) is the wireless LAN industry’s name for the IEEE frequency. If this 25 MHz channel 802.11b standard. Many WiFi devices have been marketed for wireless network- separation can’t be accommodated in a ing and these form the basis for Amateur Radio use. given area, there are other techniques that From April 2003 QST © ARRL different, so be cautious before starting your own HSMM station. If effective APC techniques can be developed, the experimenters plan to use an RF output power in the range of 2-10 W. With small, horizontally polarized dish antennas and horizontally polarized omnidirectional slot antennas, these experimenters hope to achieve in the range of 4-5 Mb/s over a range of 10 miles or more. Even greater range is possible, of course. Having favorable terrain is just as important as is power. Station identification will be accomplished dependent on the type of data being transmitted. For text messaging, call signs will be typed in, as part of the Figure 3––The Livingston County HSMM Experimenters Team displays a completed text. Normal voice identification will be slot antenna at a Christmas get-together. Left to right: Mark, AB8LN; Randy, KC8MSB; used for streaming audio. Normal Amateur John, K8OCL; Neil, K8IT; Larry, KB8QJE, and Ernst, N8EK. TV (ATV) identification methods will be used for streaming video contacts. One of the first applications to be attempted will be the use of Microsoft Figure 4––The members of the San NetMeeting for full-duplex streaming audio Antonio ARRL and video between two nodes 1.6 miles HSMM Radio Group apart.4 As experimentation progresses, shown at a recent making use of higher power and higher gain meeting. From the left: Joshua Davis, antennas, this small network will become KD5LSX; Walt a larger one, covering a wider area and DuBose, K5YFW, including many more amateurs. HSMM WG member; Jack Riegel, N5JAK; Another group has recently Jason Beens, organized—the San Antonio ARRL KBØCDN, of Sense HSMM Radio Group in San Antonio, Technologies Texas (Figure 4). Initial plans call for holding a 900 MHz radio; Ray Martinez, three to five station nodes and an AP N5VRE (standing), node, which is connected to the Internet. and Ray Ware, Their Web site is k5yfw.ham.org/. W5MLW. Getting on the Air If you want to start experimenting, you can set up your own basic HSMM station can be applied to reduce interference, inexpensive parts. They are coordinating with readily available components. The such as the use of directive antennas or their experiments with the ARRL High HSMM Working Group recommends power reduction. Speed Multimedia Working Group beginning with a LinkSys WET11 or an Caution: The ARRL HSMM Working (HSMM) and the Michigan Area ORiNOCO Wireless LAN Client, either a Group respectfully requests that all sta- Repeater Council (MARC). USB or PCMIA version, for setting up a tions using the IEEE 802.11b standard, Current plans for the Livingston point-to-point connection between two whether unlicensed (Part 15) or FCC li- County group call for using 802.11b stations. This RIC runs 30 mW and has censed (Part 97), avoid the use of Chan- channel 5 with a center frequency of provisions for an external antenna. For nel 1, 2401-2423 MHz. This is to prevent 2432 MHz. This approach will place the an antenna use a parabolic grid, which possible harmful interference to the most 22 MHz spread spectrum signal at what will provide about 24 dBi of directional prominent user of the 2.4 GHz band, the appears to be the most logical frequency gain. Use low loss coax to connect the international ser- for such testing. Approximately half of antenna to the RIC. LMR-400 cable is vices spacecraft (currently AMSAT-OS- the signal is in the experimental portion recommended for this purpose. It is low CAR 40) operating on those frequencies. of the band (2438-2450 MHz) already in cost and has 6.8 dB loss per 100 feet at designated for spread spectrum use. The 2400 MHz. Your antenna must be high Current Activity other half of the signal is in the currently enough to be in line-of-sight with the other An example of current amateur unused satellite sub-band and the station’s antenna. Try to limit the total experimentation with HSMM radio is a 2.4 GHz fast-scan ATV sub-bands. If feed line length to less than 50 feet to group of amateurs in Livingston County, interference to these users does occur, the avoid excessive power loss and be sure to Michigan, www.hsmm.us/ (see Figure 3). rules require the spread spectrum use some sort of strain relief on the RIC The group is in the process of imple- operator to correct the interference or end of the coax. menting what might be the first Amateur shut down. However, there is no known Using provided (with the card) software, Radio high speed multimedia (data, voice Amateur Radio activity on this portion of configure the RIC for ad-hoc network and video) network based on IEEE the 2.4 GHz band in Livingston County. mode, set the SSID to “hsmm” and select 802.11b technology and readily available, The situation in your area may be channel 5 (2432 MHz). Stations in your From April 2003 QST © ARRL Acknowledgments The following members of the HSMM Ham 1 Working Group made valuable contribu- tions to this article: John J. Champa, Radio Link K8OCL, Chairman, High Speed Multime- dia Working Group, [email protected]; Walt DuBose, K5YFW, HSMM Webmaster and Deployment Planning, [email protected]; Alex Fraser, N3DER, [email protected]; Jim Idelson, K1IR, HSMM Applications Data- base, [email protected]; Jeff King, WB8WKA, [email protected]; Paul L. Rinaldo, W4RI, Manager, ARRL Technical Relations, Ham 2 Ham 3 [email protected] and Neil Sablatzky, K8IT, [email protected].

Figure 5––If the stations are within range they can communicate directly without the Further Reading help of a repeater node (AP). This is known as an ad-hoc network. 802.11 Wireless Networks: The Defini- tive Guide, by Matthew S. Gast. Pub- network should choose IP addresses from ence and use our technical abilities to lished by O’Reilly & Associates, Inc, the 192.168.xxx.yyy address range.5 As an solve current problems and develop new www.oreilly.com/. Available from the initial test, try to set up two stations in the capabilities. Some of the challenges that ARRL Bookstore, www.arrl.org/shop. same room (using the RIC’s internal need to be addressed are: $44.95 plus $8 shipping ($10 outside the antennas) and enable a simple ping of the US). Order no. 8884. Tel toll-free in the • other station to test connectivity. As a Omni and directional horizontally po- US 888-277-5289, or 860-594-0355; next step, you can try using Microsoft larized antenna designs. e-mail [email protected]. • NetMeeting to establish voice and data Definition of a standard, “single board” Building Wireless Community Net- communications. Once you’re satisfied that solution for a wireless node. works, by Rob Flickenger. Published by • your configuration is good, go back to your Development of techniques to avoid co- O’Reilly & Associates, Inc, www. home locations and try the same test using channel interference. oreilly.com/. • parabolic antennas. Be sure they are aimed Development of techniques/protocols to Wireless LANs 802.11 - End to End; First accurately at each other. Hopefully, both handle a large number of users in a Edition, by Walter R. Bruce, III. Published stations will be able to connect. And wireless cell. by John Wiley & Sons, Inc, www. • remember, this is a Part 97 network. Be sure Development of low cost bidirectional wiley.com/. Available from www.fatbrain. to identify at least every 10 minutes. Figure amplifiers (amplifiers that have re- com/, a BarnesandNoble.com company. 5 shows direct ad hoc communication ceive preamps and transmit PAs along without the use of an Access Point (AP). with high speed T/R switches). Notes • Design of routing protocols to allow in- 1The HSMM web site is located at www. Initial Deployment dependent networks to be tied together. arrl.org/hsmm/. You will find additional in- • Design of Automatic Power Control formation on the current activities of the Recommendations HSMM Working Group, RLAN technology (APC) techniques. • Coordination Frequency: 446.0 MHz and links to related sites. • The use of satellite relays to tie remote 2 S. Ford, “VoIP and Amateur Radio,” QST, Feb simplex calling frequency. networks together. 2003, pp 44-47. • 3 Frequency (channel 5): 2432 MHz • Interoperability between IEEE 802.11b The Automatic Power Control (APC) rule re- center frequency (avoid channel 1). networks and other high-speed tech- quires a station’s transmit power to be reduced, • Modulation type: Direct Sequence based on the signal strength at the receiving nologies, such as the ICOM D-Star station. This is the FCC’s way of enforcing the Spread Spectrum (DSSS). system. “minimum power necessary” rule. • 4 Antenna type/polarization: Omni- • Rule changes to encourage amateur Microsoft NetMeeting is available for free download at www.microsoft.com/windows/ directional or unidirectional with spread spectrum experimentation and horizontal polarization. netmeeting/download/. networks. 5 • Addresses in the 192.168.xxx.yyy range (for Space diversity: Nodes may deploy one example: 196.168.100.010) are reserved for (primary) or both (plus secondary) AP Conclusion private networks and do not appear on the Internet. antennas. This article has described just the first • Service Set ID: hsmm. step in the evolution of the Amateur Ra- • Secondary Service Set ID (if dio High Speed Multimedia Network. As Kris I. Mraz, N5KM, was first licensed in 1967 as WN4FNR. He holds both BSEE and provisionable): hsmm/callsign. this network matures it will take on more MSEE degrees from the Georgia Institute of • Station ID method: Manually, and more ham radio characteristics. Our depending on mode of QSO: Text, Technology. Kris has 24 years of experience goal should be to enable it to evolve into at Rockwell-Collins and Alcatel USA as a voice or video. a stand-alone, nationwide Amateur Ra- • Other configurable parameters: WEP telecommunications software engineer. He dio network, with the ability to run Ama- enjoys DXing, contesting and experimenting and all encryption must be off. teur Radio applications. with HF antennas and is currently on the trail There are many Part 15 users and user- Opportunity Knocks of the final three elusive zones for 5BWAZ. groups actively looking into expanding this Kris is a member of the ARRL HSMM Work- Wireless technologies are opening up new technology. We need to look upon this ing Group. You can reach the author at new opportunities for amateurs. We can as an opportunity to recruit these experi- 470 Kinney Dr, Murphy, TX 75094 or at apply real world communication experi- menters into the Amateur Radio fold. [email protected]. From April 2003 QST © ARRL