19. Use Of WLAN, LAN, And PAN Components

Power Consumption During Intensive LAN Use

Since the introduction of Mobile Centrino Technology, any "good notebook" should include a WLAN module - at least, according to Intel. But naturally AMD also has its own devices that also work with internal WLAN modules, such as those from wireless technology vendor Broadcom. Thus, we designed the following series of tests to determine how much effect intensive use of such components has on battery lifetime in practice. The most important parameters that influence energy demand from a WLAN module include:

signal quality distance from the notebook and the WLAN access point power management of the WLAN card the device driver

Among other things, the last item is largely responsible for how heavily the CPU gets loaded during wireless communications. That is because vendors often implement software functions that could be handled in hardware to save money on production costs. This causes CPU utilization to jump noticeably, ultimately resulting in reduced battery lifetime.

This series of tests measured battery lifetime for our reference notebook used with two different mini-PCI WLAN modules from Broadcom and Intel, as well as another PC Card module (the Gigabyte GN-WMAG01).

mini-PCI WLAN modules from Intel and Broadcom

Gigabyte's GN-WMAG01 PC Card device was developed to outfit notebooks that lack integrated WLAN components

To make sure all tests ran with the same level of signal quality we took all measurements with the notebook positioned at the same constant distance from the access point (32.8 feet/10 meters). We also made sure to place the notebook in the same exact spot for each test in one of our offices, and did likewise for the access point in the next room.