47Working with the Wireless WANDepending upon the configuration of your unit, it may have theadditional wireless wide area network (WWAN) feature. Afterpurchasing a data connection plan from your local GSM cellularprovider, you can communicate from field to office, send e-mailmessages and send text messages.NOTE: When browsing the internet using the cellular connection,you must turn off the Wi-Fi (802.11) or the Nomad will default tothe Wi-Fi to browse.CAUTION: DO NOT use your Nomad while driving a moving vehicle. DO NOT remove the WWAN antenna unless directed bysupport personnel. When you are on a plane, in a medical facility or at a gasstation where wireless communication devices are not allowed,go to Wireless Manager to TURN OFF all wirelesscommunications. Simply turning the Power key off does notturn off these communications.Installing (or changing) the SIM card1. Hold down the Power key for about 3 seconds and release todisplay the power menu. Tap Replace Battery/SIM to ensurethe alarms will not wake up the Nomad.2. Remove the hand strap.3. Use a small #1 Philips head screwdriver or the screwdriver onthe end of your stylus to loosen the 4 screws in the battery door.4. Remove the battery from the unit.5. Slide the silver SIM carriage to theunlocked position (to the right).6. Gently open the hinged SIM carriagedoor, and place the SIM card (purchasedfrom your cellular service provider) intothe slot. The golden contacts should befacing down. Also ensure that the notchedcorner aligns with the angled corner onthe SIM carriage.7. Close the SIM carriage and then slide it to the locked position(to the left).8. Place the battery into the unit.