Deutsche Bank saw some green shoots of recovery in Vodafone's second quarter performance but thinks these will be more apparent in the third quarter trading update and advises investors to buy the shares ahead of the recovery.Aside from its 'buy' rating, Deutsche Bank has a 185p price on the mobile phone group.'Mobile voice volumes have suffered from deteriorating employment,' the broker said.'Though still negative, improving employment growth should see the headwind easing.'It notes that consumers have been holding off plans to upgrade to the latest smartphones though this should change.'Clear evidence of a revenue recovery would do much for Vodafone's rating,' it said.Vodafone began selling iPhones, the smartphone made by Apple, earlier this month.