Apple is rumored to release iPhone 5 in mid-October with an upgraded operating system in the form of iOS 5 that contains more than 200 new features.

iPhone 5 would also have access to Apple's iCloud service that allows users to store data such as music files on remote computer servers for download to multiple devices such as iPhones, iPods, iPads, and personal computers running Mac OS X or Microsoft Windows.

California-based Apple is expected to issue press invitations to the iPhone 5 launch on Sept. 14 and it will take place in the San Francisco Bay Area on Sept. 21, according to CultofMac. The smartphone will be released in early October with pre-orders starting Sept. 28.

This forecast falls in line with reports of Best Buy passing on the message to its employees that the iPhone 5 could be released in the first week of October.

Other rumored specifications of iPhone 5 include a near-field communication chip, a 4-inch screen, 8MP camera, world phone that would be compatible with both GSM and CDMA networks, A5 chip with at least 1.2GHz speed.

Meanwhile, speculations are rife that Apple may release the next iteration of iPhone as a 4G phone at least to Verizon and AT&T customers.

As the iPhone 5 release date nears, let's take a look at the 4G smartphones that may give tough competition to iPhone 5.

Google Nexus Prime

If rumor mills are true, Samsung and Google are readying a killer device under the name Nexus Prime, which could give iPhone 5 a run for its money in terms of both OS as well as specifications.

Nexus Prime is expected to run Android Ice Cream Sandwich and feature a Super AMOLED HD display with 720p resolution. Prime's display will include a 4.5-inch panel with a PenTile layout, according to a report from BGR.

Nexus Prime will be powered by a TI OMAP4460 chipset clocking at 1.5GHz. The report added that Nexus Prime won't feature physical Android menu buttons below the screen anymore as everything will be software-based.

In other hardware, the camera will be 5 megapixels, but the sensor is expected to be improved for higher quality images and better low-light conditions. Like many Android handsets on the market, the Nexus Prime will offer a front-facing 1-megapxiel camera for video chat.

The 5-megapixel camera, however, is said to sport an advanced sensor delivering top image quality in addition to superior low-light performance. Moreover, the device would have 4G LTE support and at least 1GB of RAM, the report added.

Google is said to be aiming to launch the device around Thanksgiving.

Motorola Droid Bionic

Motorola has released its Droid Bionic smartphone through Verizon from Sept. 8. The device would run on Android Gingerbread 2.3.4 and has powered by dual-core 1 GHz processors, 1 GB of RAM and a stunning 4.3-inch qHD display that may give a resolution of 960x540-pixels.

Verizon offers blazing 4G Internet speeds with download speeds of 5 to 12 Mbps and upload speeds of 2 to 5 Mbps in 4G LTE mobile broadband coverage areas.

Droid Bionic sports an 8 megapixel auto-focus camera with flash with 1080p HD video capture and a front-facing camera for video chat over 4G LTE, 3G or Wi-Fi.

Motorola Droid Bionic has 16GB internal storage and another 16GB microSD card preinstalled, which can be expanded up to 32GB. Verizon offers Droid Bionic at $299 with 2-year contract.

HTC Vigor

HTC is rumored to launch another Android Gingerbread smartphone in the name of HTC Vigor. It is rumored that HTC Vigor will sport a 1.5GHz dual-core processor. The phone, which is touted to be a replacement for the HTC Thunderbolt, is expected to don a 4.3-inch display with 1280x720 screen resolution.

Vigor is surmised to be fitted with an 8MP camera and expected to offer 1GB RAM, 16GB internal storage and is also surmised to incorporate Beats Electronics Technology - best known for the high-performance line of headphones backed by hip-hop artist /producer Dr. Dre.

Samsung Galaxy S2 LTE:

Samsung recently showcased its Samsung Galaxy S2 LTE phone at IFA Germany. The Galaxy S2 LTE is a larger cousin of Galaxy S2 both in terms of size and hardware specifications.

The Galaxy S2 LTE sports a 4.5-inch Super AMOLED Plus display with 800x480 screen resolution. It is powered by a 1.5GHz dual-core processor and offers 16GB internal memory.  The phone is 0.37-inch thick and weighs 4.6oz. Galaxy S2 LTE will also feature an 8MP rear-facing and 2MP front-facing cameras. It is fitted with a Li-on 1850 mAh battery. The phone will come pre-loaded with Android Gingerbread.

Samsung Stratosphere:

Recently Engadget spotted Samsung Stratosphere codenamed SCH-i405 in an FCC filing. The phone with a QWERTY sliding keyboard is rumored to be destined for Verizon's LTE network. The smartphone would run on Android Gingerbread and will feature a 4-inch Super AMOLED screen with 800x480 resolution. It is expected to be powered by a 1GHz single-core processor. It offers 512MB of RAM, 1800mAh battery and a 5-megapixel rear and a 1.3-megapixel front camera and 2GB of internal storage.