multithreading - Upload sensor data from Android device to remote host

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I want to develop an
Android application that satisfies the following
specifications:

• Record
  data from a sensor (for example the accelerometer) at an
  approximate rate of
  10-30 Hz.


• Upload this raw data to a remote server (for
  example using TCP
  sockets).


• The user interface
  should be minimum, just a pair of buttons to start
  or stop the recording and
  transmission of the data.



• All the process
  should be unnoticeable for the user and keep working
  when the screen goes off
  for several hours.


• Battery life is not critical (it
  should last several
  hours).

Vision: I would
like to analyse in quasi-real time the sensor measurements of a group of users without
their intervention (apart from starting the
application).

After some research, I could
manage to perform these tasks separately and inefficiently. I've tried classes such as
Service and IntentService, SensorEventListener, etc. I don't know if I should use
Thread, Service or IntentService for each task. Specifically, I have serious problems to
communicate them.

My questions:

1. What class(es)
   do you recommend to use in order to solve
   this
   problem?


2. What task should be done on each
   of them?


3. If the tasks are performed in different entities
   (threads, services,
   intentservices, etc.), how should I intercommunicate them
   (I'm
   thinking about the recording and uploading
   tasks)?

I am
asking for the best-practice structure to solve my problem. You do not need to go into
details in terms of developing/coding the
solution.

Thank you very much and feel free to
ask if something is not clear
enough.

David

UPDATE:

After
some more research and thanks to DROIDcoder, I manage to design a skeleton for my
app:

• Main UI:
  Activity object presenting two buttons (start/stop) that
  will launch a Service
  with the usual startService/stopService
  methods


• Background: Service
  object
  
  

As
this is only a proposition, I add it as an edition. I will post a detailed answer when
the whole system works.

The questions
remains: can you think about a better design for the
application?

Thanks again!

Answer

Finally what I have
done:

Issue 1: record data from a sensor on the
background for a long period of time.
Solved using the class
Service to initialize the sensor and listen for
callbacks.

Issue 2: communicate the Activity
class holding the UI with the Service class.

Solved using the
startService(Intent myMessage) method from the Activity
class combined with a switch in the onStartCommand() method
from the Service class to classify the message.

Issue 3: communicate the Service class with the
Activity class.
Solved registering a custom
BroadcastReceiver in the Activity and sending
Intents from the Service. I've used it to update a progress
bar (in the Activity) during the file uploading (in the Service). An exceptional
tutorial can be found href="http://www.vogella.com/tutorials/AndroidBroadcastReceiver/article.html"
rel="nofollow
noreferrer">here.

Issue 4: upload
data to a remote server.
Solved using AsyncTask
inside the Service like in href="https://stackoverflow.com/questions/18289623/how-to-use-asynctask/18289746#18289746">this
site.