CB-radio in road traffic as social network and information technology

1. CB-radio in road trafficas social networkand information technology Ing. Martin Adámek Department of Information Technologies Faculty of Informatics and Management University of Hradec Králové, Czech rep. SoNet September 2010

2. CB radio • Transceivers, free accessible for public • Citizen band (civil band) • band around 27 MHz • in CZ: lot of trucks, some vans, few off-roads, rarely passenger car • absolutely unknown technology for the most of people • in PL: lot of cars, including passenger ones (sharp police & fast drivers) • almost everyone knows it Martin Adámek (KIT FIM UHK) CB as so.net. & IT

3. CB radio – brief history • Way of using being changed in time • available ca. since beginning of 90’s, when: • GSM cell phones N/A • price of NMT mobile phone ca. 6 month salaries + high charges • waiting for fixed phone e.g. 3 years (even if with shared line) => CB: communication technology for families, companies, organisations, friends (emergency channel no.9 used to be monitored by EMS, Police or Metro Police in CZ) • beginning of 21st century: • 2nd-hand function mobile phone free of pay, low charges • for sport, outdoor and even organising also available PMR 446 MHz hand transceivers (lower price, lower size and weight, lower battery consumption, lower but usable range) => CB: almost being used already by drivers only Martin Adámek (KIT FIM UHK) CB as so.net. & IT

4. Technical principles • no repeaters (direct transmitting from transceiver to receiver) => limited range • range depending mostly on equipment of transmitting side • and position of each participant (receiving of disturbing signals) • in some distance connection can be available in 1 direction only (stronger->weaker; not back) • in group communication can be that: • B have connection with A and C, but A and C do not have connection with each other • and all combinations (A hears C, C does not hear A...) • halfduplex • switching of each station between transmitting and receiving mode • max.1 transmitting station on 1 channel (else signal disturbing) • open band, accessible for everyone • road traffic: • ch 10 FM in CZ, ch 19 AM in PL (ch10cz ≠ch10pl) • real range depends on conditions and state of equipment: ca. 100m (broken ant.) to ca. 40km (amp.) on normal road Martin Adámek (KIT FIM UHK) CB as so.net. & IT

5. Various range of transmitting A B C Martin Adámek (KIT FIM UHK) CB as so.net. & IT

6. Social network • CB available ca. since beginning of 90’s • without obligation of registration ca. since 1/3 of 90’s • term „social network“ is newer than CB • network of people equipped by transceivers • it can not be function without people • small roads with low road (and radio) traffic • after midnight when low traffic • in CZ: weekends (truck driving prohibited; passenger cars not equipped by CBs) Martin Adámek (KIT FIM UHK) CB as so.net. & IT

7. Information technology • each information turning around in circle in some definite limited (=> related) location around place of occurrence of event • being repeated during whole period of validity of information • CB-radio versus radio broadcast • broadcast has unacceptable delay (considering program schedule) • lot of broadcast stations exist; almost none info. sharing • broadcasting is for whole country or big region • CB is instant and local => provides related information • it is possible to ask on CB (generally on ch. xor concrete) • about traffic information, about navigation problem Martin Adámek (KIT FIM UHK) CB as so.net. & IT

8. One of often real scenarios (simplified) Pha HK, NA B: (general channel ask, xor to A) How does it look in direction to NA? A: Ok up to HK. B: Thanks, you have it clean up to Pha. C: How was it?, I have not received. B: Ok up to HK. C: Thanks. < A B > C > Martin Adámek (KIT FIM UHK) CB as so.net. & IT

9. Comparison & resume empirically: • CB radio is much better than broadcast radio for traffic information • but limited by type of road and week-day+time (demanding truck traffic) • based on ca. 15 years personal experience of using CB radio in the car Martin Adámek (KIT FIM UHK) CB as so.net. & IT

10. Comparison & resume scientfistifically: • searching suitable method just now • monitoring of CB traffic and other information sources – NDIC website, radios broadcasting (not radar info on public channels), Czech and Polish CB band, radary.cz (SMS) • in traffic knot like Náchod or Hradec Králové • on some main road during some traffic event (radar measurement) • monitoring of frequency of repeating of the same information • watching how much of drivers paying penalty for over-speed have CB and why they did not know about radar • watching of driving-light signals Martin Adámek (KIT FIM UHK) CB as so.net. & IT

11. Comparison & resume • % searching suitable method just now • operation of central CB information service in traffic knot (normal in Prague, sometimes in Brno –hobby of disabled people) and logging of information float into protocol • counting of cars equiped by CB antenna, with information about category of vehicle and country of registration • watching how much of drivers of cars with CB antenna really watch radio traffic on driver’s channel • everything for various types (sizes) of roads, various days, various time • watching of traffic information and comparing with real state during driving Martin Adámek (KIT FIM UHK) CB as so.net. & IT

12. Summary • CB provides much more location-relevant information, in much shorter time (the same road, few seconds) than radio broadcast (whole country, tens of minutes) • information about traffic accident in few seconds (users of CBs informed faster then police) • necessity of verification some acceptable way Martin Adámek (KIT FIM UHK) CB as so.net. & IT

13. Questions? • Antennas for receiving and transm. of information: • 89,7 MHz FM Rx(ČRo1 - Radiožurnál) • 27,180 MHz AM Rx/Tx(CB, Polish ch. 19) • 27,075 MHz FM Rx/Tx(CB, Czech ch. 10) Thanks for your attention. Martin Adámek (KIT FIM UHK) CB as so.net. & IT [www.adamek.cz]