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.