1. Field of the Invention
This invention relates to the downloading of application programs over a wireless network. More particularly, the invention concerns the individual estimating and display of a length of time to download an application program over a wireless network to a remote module, such as a wireless device, based on calculated data transfer rates.
2. Description of the Related Art
Wireless technology is rapidly evolving and is playing an increasing role in the lives of people throughout the world. Ever-larger numbers of people are relying on this technology directly or indirectly. Wireless technology involves telecommunications in which electromagnetic waves (rather than some form of wire) carry signals over part or all of a communication path. Wireless devices constitute a visible implementation of wireless technology.
Today's wireless devices contain special circuits, such as application-specific integrated circuits (“ASICs”), capable of running a variety of application programs including some that would otherwise run on computers. These application programs include games, books, and information content programs (such as news information, stock quotes, up-to-date weather information, or air flight times and information). These applications may be downloaded onto the wireless devices at the time they are manufactured or later over-the-air using electromagnetic waves.
With the anticipated proliferation of the downloading of programs over-the-air, it will be increasingly important for a user of a wireless device to know how much time is required to download the programs. For example, if the user pays per minute of air-time, the user will want to know how long the download will take, so that the user will have some idea of how much the download will cost (in addition to the cost of the application program, if a charge is associated with the download itself).
However, the length of time required to download application programs over-the-air is extremely variable. The data transfer rate (the rate at which data is transferred wirelessly to a wireless device) changes, in part, due to the inherently dynamic nature of signal-to-noise ratios. In analog and digital communications, the signal-to-noise ratio (“S/N”) is a measure of signal strength relative to background noise. “Noise” is unwanted electrical or electromagnetic energy that degrades the quality of signals and data. Noise can affect any communications regardless of content, such as text, programs, images, audio, and telemetry. The higher the SIN ratio, the faster the wireless device will be able to download an application program.
One reason for changes in S/N ratio is that wireless devices are mobile, leaving the S/N ratio subject to change because the user of the wireless device is moving (such as in a vehicle) either away from a signal, into a tunnel where the signal cannot reach, or in some other manner adversely affecting the S/N ratio.
In addition to the mobile nature of wireless devices, another factor that influences S/N ratio (and thus data transfer rates) is the communications mode of the wireless device. For example, wireless devices utilizing cdmaOne technology, developed by QUALCOMM Incorporated, are capable of achieving a maximum data transfer rate of up to 14.4 kilobits per second. Telephones utilizing the next generation of wireless devices (3G), such as those using CDMA2000 technology, developed by QUALCOMM Incorporated, will be capable of achieving data transfer rates of 115 kilobits per second. Other new products, such as those using the 1×EV technology, developed by QUALCOMM Incorporated, have data transfer rates of 2.4 megabits per second.
Still another factor that influences S/N ratio is electromagnetic interference. Any device or system that generates an electromagnetic field in the radio frequency spectrum may potentially disrupt the operation of wireless devices. Wireless transmitters (such as radio or television transmitters) can produce electromagnetic fields strong enough to severely affect the S/N ratio. For example, although the maximum data transfer rate for cdmaOne technology is 14.4 kilobits per second, due to interfering electromagnetic energy and an uncontrollable radio frequency environment, the average actual data transfer rate for the cdmaOne technology is 9.6 kilobits per second.
For these reasons, it is impossible to determine, in advance, the data transfer rate for wireless devices, as data transfer rates are greatly affected by the mobile nature of wireless devices, the communications mode of the telephone, and electromagnetic interference. Consequently, it would be extremely difficult to provide an accurate estimate, in advance, of the length of time required to download an application program over-the-air onto a wireless device.
In addressing the foregoing concerns, one approach might be to look at download estimates displayed by personal computers. However, computer estimates for the length of time to download application programs have traditionally been calculated based on the size of the application program and the modem speed, both of which are constant numbers. In addition, download estimates for computer programs over the internet are often inaccurate. The computer has no information about the data transfer rates between various outside components of the internet (for example, other outside servers) that may affect the downloading time for a particular program. Thus, in download estimates for computer programs, there is no examination of the data transfer rates immediately preceding a download that might significantly affect the estimate.
As discussed above, the data transfer rates for wireless devices are not constant and vary depending on different factors affecting the S/N ratio. Consequently, certain unsolved problems are to be expected in future attempts to estimate download times of application programs onto wireless devices.