Apple sent out invitation to press on Tuesday, announcing that it will hold its next iPhone event on October 4. It is expected the company will launch iPhone 5 or iPhone 4S - or both - at the event. Though there is no official confirmation that two models of iPhone will be launched, analysts believe that to counter adoption of Android, Apple will offer a cheaper version of iPhone for developing markets. Recently, Al Gore, a former vice president of the US and a member of Apple's board, said that "new iPhones" will launch in October. It is expected that iPhone 5 will pack a dual-core processor, an 8 mega-pixel camera and 1GB RAM. Keeping in line with Apple's attempt to slim down devices with each new release, it may eschew the glass and metal frame of iPhone 4 for a sleeker unibody aluminum shell. Some analysts believe that to take on big Android smartphones that have become increasingly popular in the last one year, Apple may also bump the screen size in its next iPhone. Two days ago reports surfaced that the next iPhone will come with a feature called Assistant that will enable a number of voice-based commands and allow users to "talk" to their phone. Apple has titled October 4 even as "let's talk iPhone," something that hints at the possibility of Assistant. The next iPhone will be powered by iOS 5 and Apple is expected to announce the availability of the OS on October 4. The new OS also supports iPhone 4 and iPhone 3GS. The October 4 event will be Apple's first media event after Steve Jobs resigned from CEO's post. Hence the keynote address, made famous by Jobs, will likely be delivered by current CEO Tim Cook.