Radio & Cellular Communications

Session Five Radio & Cellular Communications Learning Objectives: ? Explain the capabilities and limitations of two-way radio systems. ? Explain the capabilities and limitations of cellular communication systems. ? Be able to compare and contrast the main differences between the two. Things to research and facts to know: 1. Wireless basics a. Frequency Spectrum: “DC to Daylight” b. FCC (http://wireless.fcc.gov/) c. NTIA (http://www.ntia.doc.gov/osmhome/osmhome.html) 2. Radio bands: frequencies / wavelength Extremely Low Frequency: 3 – 30 Hz / 100,000m – 1000km Super Low Frequency: 30 – 300 Hz / 1000km – 100km Ultra Low Frequency: 300 – 3000 Hz / 1000km – 100km Very Low Frequency: 3–30 kHz / 100-10km (submarines, beacons) Low Frequency: 30–300 kHz / 10-1km (time & navigation signals) Medium Frequency: 300–3000 kHz / 1000 – 100m (AM radio) High Frequency: 3–30 MHz / 100m – 10m Very High Frequency: 30–300 MHz / 10m – 1m (FM radio, TV) Ultra High Frequency: 300–3000 MHz/ 100cm – 10cm (TV, wireless LAN) Super High Frequency: 3–30 GHz / 10cm – 1cm (wireless LAN, microwave) Extremely High Frequency: 30–300 GHz / 10 mm – 1 mm 3. Propagation (http://en.wikipedia.org/wiki/Radio_propagation) a. Line of sight b. Radio horizon: ARRL suggest 1.415, others just round up and use 2 as the multiplier. An antenna at 6 feet can “see” a maximum of 3 miles over open/flat area. 20 feet provides 5½ miles. 500 feet provides 27 miles. See the graphic at http://en.wikipedia.org/wiki/File:How_far_away_is_the_horizon.png c. Ionosphere (http://en.wikipedia.org/wiki/Ionosphere) The outermost part of the atmosphere. Layers: D (day only, absorbs HF), E (day/night), and F (night) & F1, F2 (deforms during day). d. Atmosphere absorption See graphic at http://en.wikipedia.org/wiki/File:Atmospheric_electromagnetic_opacity.svg e. Atmosphere interference (bending, bouncing) f. Skip zones 4. Two-Way Radio Types a. Analog & digital b. Direct & repeater c. Conventional & trunked radio d. Bands: (aka FCC “Wireless Services”) include private land mobile (which contains public safety and industrial/business), amateur (“ham radio”), FRS/GMRS, and citizens band (CB – “Breaker, breaker one-nine, ya’ got a Smokey in a plain brown wrapper at milepost sixty-seven.”). 5. Cellular Communications a. Macrocell, Microcell, Picocell, and Femtocell (longest practical range is 20 miles) b. TDMA & CDMA c. GSM: Global System for Mobile Communications [AT&T] (voice & SMS; majority of global market uses this standard) d. Review the chart at http://en.wikipedia.org/wiki/Comparison_of_wireless_data_standards Look specifically for GPRS, EDGE, EV-DO, LTE and HSPA+, and compare the speeds. e. 4G: Review http://en.wikipedia.org/wiki/4G. Note that no US cellular carrier meets the definition of 4G yet they all use the name. Why? A thought about cellular standards: China Mobile is the largest single mobile phone operator with the largest network and 781.08 million subscribers (1st quarter of 2014). China Mobile uses a GSM network and it building the 3G/4G network. The total number of mobile service subscribers in China from the top 3 companies is now over 1 billion. For comparison, the entire US population is about 318 million. China Mobile is also ranked number one based on revenue in excess of US$20 billion. Vodaphone Group is number two mobile operator based on revenue at more than US$15 billion. Samsung Electronics is the largest manufacturer of mobile phones with 31.3% of the global smartphone market share in 2013 and nearly 24% of the overall mobile phone manufacturing market. China Mobile, Vodaphone Group and Samsung all have a strategic vision of GSM and LTE. Weekly Schedule: Session Topic/Objective Required Readings and Assignments 5 Oct 11 - Oct 18 Topic: Radio and cellular communications Objective: Explain the capabilities and limitations of two-way radio and cellular communication systems, and be able to compare and contrast the main differences. Readings: ? How far will this radio go? http://keith.robertory.com/?p=672 ? Radio types and bands http://keith.robertory.com/?p=674 ? Homeland Security Affairs, Interoperability: Stop Blaming the Radio (2007). Retrieved from https://www.hsaj.org/articles/153 ? Radio Reference. (n.d.). Trunking basics. Retrieved from http://wiki.radioreference.com/index.php/Trunking_Basics ? Understanding propagation. (More than you probably ever need to know) http://www.hamqsl.com/Understanding%20Propagation.pdf ? Propagation http://en.wikipedia.org/wiki/Radio_propagation ? Cellular communications http://keith.robertory.com/?p=676 ? The possibility of 4G http://keith.robertory.com/?p=611 ? Mobile applications on the rise in the enterprise http://www.business.att.com/content/whitepaper/mobile-applications-on-the-rise.pdf ? Comparison of wireless data standards http://en.wikipedia.org/wiki/Comparison_of_wireless_data_standards ? 4G (Take special note of the data speed requirements to be 4G) http://en.wikipedia.org/wiki/4G ? Software Defined Radio (EMAN620-2168 Group Project) Assignments: ? Review Week 5 of Course Content. ? Respond to Week 5 Discussion.