updated service doc

docs/developers/android_service.md

@@ -39,12 +39,45 @@ Please note: when they have a parameter 'weight' the result is not an absolute n
 
 This parameters are needed to tell BRouter what to do.
 
+### using profiles
+
+For calulation BRouter uses a set of rules defined in a profile. See description of profile [rules](https://github.com/abrensch/brouter/blob/master/docs/developers/profile_developers_guide.md).
+
+Here we talk about how we let BRouter know witch profile to use.
+There are three ways:
+
+1. use the parameter 'v' and 'fast'
+```
+   "v"-->[motorcar|bicycle|foot]
+   "fast"-->[0|1]
+   This enables BRouter to look into the file serviceconfig.dat.
+   In there BRouter find the profile associated for e.g bicyle_fast trekking
+   This could be changed by the user calling the BRouter app server-mode.
+```
+
+2. use the profile parameter
+```
+   profile=trekking
+   It needs an available file in the BRouter profile folder e.g. trekking.brf
+```
+
+3. use a remote profile
+```
+   remoteProfile=a long string with routing rules
+   This is saved in BRouter profile folder temporary with the file name 'remote.brf'
+```
+
+
 ### profile parameter
 
 Profile parameters affect the result of a profile.
+The variables inside a profile predefine a value e.g. avoidsteps=1
+A parameter call gives the chance to change this start value without changing the profile e.g. avoidsteps=0
 For the app it is a list of params concatenated by '&'. E.g. extraParams=avoidferry=1&avoidsteps=0
 The server calls profile params by a prefix 'profile:'. E.g. ...&profile:avoidferry=1&profile:avoidsteps=0
 
+By using this parameter logic, there is no need to edit a profile before sending.
+
 ### using profile parameter inside an app
 
 To be flexible it is possible to send a profile to BRouter - server or app.