Wireless control of Bluetooth “on/off” switches in a smart home using
J2ME in Mobile Phones and PDAs.
Luis Carlos Aceves Gutiérrez
Universidad de Monterrey
Av. Morones Prieto 4500 pte., 66220, San Pedro Garza Garcia, Nuevo León, México http://www.udem.edu.mx/ laceves@udem.edu.mx
Og Jamir Ramos Juraidini
Universidad de Monterrey
Av. Morones Prieto 4500 pte., 66220, San Pedro Garza Garcia, Nuevo León, México http://www.udem.edu.mx/ jamiros@gmail.com
Carlos Alberto Garza Frias
Universidad de Monterrey
Av. Morones Prieto 4500 pte., 66220, San Pedro Garza Garcia, Nuevo León, México http://www.udem.edu.mx/ karlytoz@gmail.com

Abstract
This work focuses on the idea of manipulating a manufactured on/off switch with a Bluetooth receiver, using a JAVA compatible mobile device or PDA through the L2CAP protocol. The main goal is to remove wires from a smart home infrastructure. Keywords: Bluetooth, Smart Homes, MIDlets, J2ME, Home Automation, Smart Phones

1. INTRODUCTION
This document identifies the simple process used in a daily basis in a standard home and how we can automate this process with the implementation of manufactured Bluetooth on/off switches which receive a signal from a mobile device or PDA that is compatible with JAVA and Bluetooth. To achieve this we send a 1 or a 0 through the L2CAP protocol so that the switch perceives an on or an off.

2. BLUETOOTH AND WIFI
Bluetooth was selected as our way of communicating PDA/Mobile with a central system. The reason Bluetooth was selected over Bluetooth for various reasons. First of all, Bluetooth security is less complex and more stable than that of
WiFi. Bluetooth manages a security measure of only permitting certain selected devices to interact with them; WiFi in the other hand establishes a WEP key that has been known to be cracked. Another reason that Bluetooth was selected over WiFi, is that Bluetooth has a shorter range of signal emission than Wifi. This is a pro because the shorter the range the less the amount intruders that will try to infiltrate your home system. [3]
Bluetooth also has some major draw backs. Some Bluetooth components’ compatibility with certain operating systems are not supported, also some programming languages still haven’t developed libraries to interact with this communication protocol. Installation, real life reception, speed and many compatibility problems are encountered with this form of communication. [3]

3. L2CAP
L2CAP or Logical Link Control and Adaptation Protocol was used in the communication between client and server due that it is one of the lower levels of communication in the Bluetooth Protocol. Since L2CAP is lower level the type of data that is sent either to the client or the server is more primitive and not complicated such as OBEX (Object
Exchange) which is high level and sends a certain type of data. In MIDlet programming there are two types of communication objects for Bluetooth. One is SPP and the other is L2CAP, a connection object is instantiated in the client and the server program of either type. A URL is made to set which is the server “btl2cap://”, once this is established a UUID is set to show the address to the client so it can be identified. [3]

4. LIGHTING, SECURITY AND APPLIANCE CONTROL WITH BLUETOOTH
Currently we haven’t found a manufactured Bluetooth on/off switch with this capability, but as a supposed scenario an on/off switch receives a 1 or 0 signal sent from a mobile device or PDA compatible with JAVA and Bluetooth. A basic system architecture that could be considered is the following, which could be seen in figure 1:

mobile

Illumination

Habitant

PDA

Security

Appliances
PAN
Home

Figure 1. Architecture for Mobile/PDA interaction through Bluetooth
Inside a PAN (Personal Area Network) a user with his PDA device or Smart Phone accesses the client program in
JAVA. This program then accesses the PAN through Bluetooth Protocol and sees