Cell and Cellular Traffic-I

= Test yourself, answer these questions =


 * In a cell phone system what is a cell?
 * Why does the mobile phone cell have a hexagonal shape?
 * What is co-channel interference? How do I reduce it?
 * Prove that for a hexagonal geometry, the co-channel reuse ratio is given by Q=sqrt(3N), where N= i^2+ij+j^2.
 * A cellular service provider decides to use a digital TDMA scheme which can tolerate a signal-to-interference ratio of 15 dB in the worst case. Find the optimal value of N for omni-directional antennas, 120 degrees sectoring antennas and 60 degrees sectoring antennas. (Path loss exponent v = 4, number of interfering cells I = 6 (omni-directional antennas), I = 2 (120 sectoring) and I = 1 (60 sectoring).
 * What is Cell splitting and what benefits it brings? Where we should use smaller cell and where we should use bigger cell and why?
 * What is outage and how is it rated with fading?

= Lecture 2015=
 * [[Media:UNIK4230-Lecture-5-Cells and Traffic-2015-0312.pdf]]
 * Video: http://lux.unik.no/unik4230-ak/unik-20150312.wmv

= Lecture 2014=
 * [[Media:UNIK4230-Cell-L6_and_7-2014.pdf]]
 * Video: Video: http://lux.unik.no/unik4230-ak/unik-20140313.wmv

= Documentation from 2013 =
 * [[Media:UNIK4230-Cell-L6_and_7-2013.pdf]]
 * Video:

= Documentation from 2012 =
 * [[Media:UNIK4230-Cell-L6_and_7-2012_Final.pdf]]
 * Video: mms://lux.unik.no/unik4230-ak/unik-20120301.wmv

= Other info =
 * Book: [[Media:UNIK4230-CHAPTER-4.pdf]]
 * Erlang table (from the book, pages 158-159): [[Media:UNIK4230-Erlang-Table.pdf]]

Evolution of cells
From Macro to micro, pico and femto cells. Macro cells are used for coverage and fast moving objects (cars), micro cells are typically used for capacity, pico cells are cells for hot spots (train station, office building) and femto cells are for home/small office use.

Examples of Pico cells (also called metro cells)
 * Nokia Siemens Networks: http://pt.nokiasiemensnetworks.com/news-events/press-room/press-releases/flexi-zone-quenches-thirst-for-mobile-broadband-slashes-cost-per-bit-mwc12
 * Alcatel Lucent "lightRadio": http://www.evernote.com/shard/s94/sh/8b44af9f-a498-4d37-87f3-5a9756efb4e7/a401c72384d9440f19e6752510ccf907 (source: Teknisk ukeblad 0812, http://tu.no); http://www.dailywireless.org/2011/02/07/lightradio-mini-modular-cell-infrastructure/
 * Ericsson: http://www.lightreading.com/document.asp?doc_id=204190