The iPhone 6, iPhone 5S release date may be sooner than later as US carrier T-Mobile lowered the contract price of the current iPhone 5.

There are rumours that the next generation of Apple's iPhone will arrive soon as T-Mobile offers discount on the current iPhone 5. The iPhone 5's price has been slashed to just $145.99 upfront on a two-year T-Mobile contract.

The iPhone 5 was available for $99 when it first launched in April, but this was raised to $149.99 in May, after the promotional period.

T-Mobile then increased the iPhone 5 price by $50. Now, T-Mobile has dropped the upfront payment again to $145.99 suggesting a new iPhone may be on its way. However, there is a catch to this as the carrier has also increased the monthly payment, by $1 a month.

Carriers have a habit of dropping the prices of its devices when a new update is announced, usually, to get rid of stock and clear space for the new device. T-Mobile's reduction may be more expensive in the long run, but customers are more tempted to buy if the upfront cost is lowered.

The change in pricing means the device will cost you as much over a 24-month contract as it would if you bought the device unsubsidized from Apple. The 32GB iPhone 5 will cost $245.99 and the 64GB $345.99.

The next iPhone is rumoured to feature Retina or IGZO screen display, A7 quad core chip processor, iOS 7, 128GB internal storage, 13 mega-pixel camera, and longer battery life. The lack of NFC support on the iPhone 5 was one of the biggest criticisms aimed at Apple's smartphone.

Meanwhile, the cheaper iPhone 5S is rumoured to sport a plastic casing, 4-inch screen display, dual core processor and 8-megapixel camera. The smartphone is speculated to be available in five to six different colors.

Both Apple smartphones are rumoured to include a fingerprint sensor technology for added security. The rumour is strengthened by the report that Apple bought a fingerprint technology firm Authentec last year.

It is initially reported that the new iPhones will be launched in September. The Apple chief Tim Cook also dropped several hints that the upcoming iPhone 6 and 5S will be released later this year. Cook said that no new products are to launch before the end of the year.

However, In the D11 interview of Apple's chief Tim Cook subtly suggested that the company will not release a low cost iPhone or a phablet this year. Tim Cook stressed that Apple invests time and effort in making each phone that serves various markets rather than making a myriad of phones aim to serve specific users.