Wireless networking is a technology that allows computers and other electronic devices to have network connectivity using radio waves instead of wires. While this opens up new possibilities for mobile connectivity, it must be remembered that the wireless network is an institutional resource made available for the benefit of the Caltech community. The use of all computers, mobile devices, and other wireless devices is subject to the Network Policy Regarding Devices Connected to the Caltech Network and the Institute Policy on Acceptable Use of Electronic Information Resources.
Factors Affecting Network Connectivity
Wireless networks depend on the ability to transmit and receive radio waves which makes them fundamentally different from wired networks. The strength of the radio signal used to establish the network connection is affected by factors such as:
- A computer's distance from wireless access point
- A building's construction
- The materials used in making the building
- The presence of interference; this includes vegetation and other water sources
- The number of computers connected to the same access point: all users are sharing the same radio signal unlike a wired Ethernet connection where each user has a distinct connection to the network.
Are you experiencing issues with the Wireless Network?
Wireless networks are intended to provide network connectivity in environments where network wiring is not practical or the users are highly mobile. It is provided to campus users as a convenience to facilitate research and learning. Wireless is not a substitute for a wired network. If you are having problems with the wired network please do not use the wireless as a substitute, please use the contact information below for assistance:
- To have wired network problems corrected or additional ports installed - http://help.caltech.edu (request type IMSS-->Network, Wireless & Remote Access-->Other)
- To request wireless access where it is non-existent or very limited, and you think it should be improved - http://help.caltech.edu (request type IMSS-->Network, Wireless & Remote Access-->Other)
Are you planning a conference and need wireless access for your guests?
If you are sponsoring a conference or meeting where a sizeable group of non-Caltech users will want wireless access, please consider having your users access the Caltech Guest wireless network. If this network does not meet your requirements, you may request, with at least one week advance notice, a temporary conference network by submitting a request at http://help.caltech.edu (request type IMSS-->Network, Wireless & Remote Access-->Wireless Conference). There is a one-time charge of $250 for setting up the temporary network. If you need wireless coverage for a conference in an area that does not already have coverage, or you need additional coverage, please contact us as soon as possible, but not later than two weeks in advance of the event, to see if we can support your requirements. There will be additional charges, depending on the support requirements.
Policy Regarding Non-IMSS Access Points and Wireless Routers
Wireless networking uses the 2.4 GHz (and in the future 5 GHz) frequency bands, an unlicensed band used by such devices as cordless phones, Bluetooth devices, some lighting control systems, and microwave ovens as well as wireless networking. Any of these devices can potentially interfere with wireless networking. Since all devices must use the same radio frequency range to make their connection, access is shared among all devices. This is very similar to the old 10 Megabit shared Ethernet, where all devices were connected to the same wire. It works well for a small number of devices, but as the number of devices grows, so does contention for access. The result is slow network speeds and dropped connections. Wireless networking is additionally impacted by the effect of non-network devices and signal multipath (reflections) within the radio frequency range.
The access points operated by IMSS are connected to controller hardware that causes them to work together. Access points and wireless routers not installed by IMSS will cause interference. There are 3 frequency ranges corresponding to channels 1, 6, and 11 that do not overlap each other. All three of these are used by IMSS to provide the best service. Wireless devices configured on these channels will be in direct contention with the Caltech wireless network. Choosing one of the other channels will not avoid interference; these channels do overlap into channels 1, 6 and 11. The result will be signal degradation for the Caltech wireless network.
Wireless access points and routers are subject to the Network Policy Regarding Devices Connected to the Caltech Network and the Institute Policy on Acceptable Use of Electronic Information Resources as are any devices that are connected to the network. IMSS reserves the right to disconnect any device (wireless or otherwise) that is found to be interfering with the operation of the network.