(Telecompaper) Airtel Kenya has launched its 4G service and is running a promotional double data offer for customers who have a 4G handset and relevant SIM card. In addition, any Airtel customer who upgrades their SIM to LTE will get a 2 GB bonus free. Customers can self-upgrade their SIM by dialing star 100 hash and selecting the upgrade menu and can get a 4G SIM free of charge from any Airtel shop.