From b4bbac8d5c3835a0c6516e40b2fdcdc42848e17a Mon Sep 17 00:00:00 2001
From: Refik Hadzialic
Date: Wed, 6 Jun 2012 18:47:38 +0200
Subject: GPS Picture

---
 vorlagen/thesis/src/kapitel_A.tex | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

(limited to 'vorlagen/thesis/src/kapitel_A.tex')

diff --git a/vorlagen/thesis/src/kapitel_A.tex b/vorlagen/thesis/src/kapitel_A.tex
index 35a0367..444bb77 100644
--- a/vorlagen/thesis/src/kapitel_A.tex
+++ b/vorlagen/thesis/src/kapitel_A.tex
@@ -430,6 +430,22 @@ To increase the speed of measurement report, reference time can be used to provi
 information for the A-GPS in the MS of target entity. This field is of boolean
 type, if set to true, reference time is included in the sent packets. 
 
+Since the sent packets are not transmitted in real time but put on a stack and 
+then sent to the MS, a time delay exists. A solution to this problem is to 
+add extra seconds to the reference time being sent. In order to assess
+the amount of extra seconds to add, the GSM operator is required experimentally
+to verify his/her findings. \todo{see how much the reference time can deviate from current time}.
+
+The reference time being sent to the MS is Coordinated Universal Time (UTC). The GPS device 
+receives UTC time from the satellites and adjusts the computer time. To set the correct 
+time, time zone offset of the BTS ought to be set correctly.
+
+Finally, the refresh time of downloading new almanac and ephemeris data has to be set.
+The variable uses the hour unit, how often the data are being downloaded. If the data are
+used from a local GNSS station, refresh time of the ephemeris data should be set to
+every 30 minutes or 0.5 hours. The almanac data are valid for up to 180 days \citep{GPS-Guide} but are updated
+usually every day\footnote{Almanac update times can be found here:
+\url{http://www.navcen.uscg.gov/?pageName=currentNanus&format=txt}} \citep{GPS-Pentagon}
 \newpage
 
 \section{Sourcecode}
-- 
cgit v1.2.3-55-g7522

