Your organization uses an 802.11b wireless network. Recently, other tenants installed the following equipment in your building: a wireless tv distribution system running at 2.4 GHs, a wireless phone system running at 5.8 GHz, a wireless phone system running at 900 MHz, an 802.11a wireless network running at 5.75 GHz.
Since the equipment was installed, your wireless network has been experiencing significant interference. Which system is to blame?