Constructing a wireless campus network can be divided into two parts: indoor and outdoor.
1. Indoor
Refers to classrooms, conference rooms, temporary mobile offices and other rooms that were not originally equipped with wired networks.
The first step in deploying WLAN indoors is to determine the number and location of APs. That is to say, the respective wireless signal coverage areas formed by multiple APs must be cross-covered, and each coverage area must be seamlessly connected. All APs are connected to the wired backbone network through twisted pairs, forming a large service area based on the wired network and extended by wireless coverage. All wireless terminals access the network through the nearest AP and access the entire network resources.
Gaps in coverage areas can cause connectivity within these areas to be unavailable. Installers can determine the location and number of APs through site surveys. The location survey can weigh the actual environment (such as the size of the classroom, etc.) and user needs, taking into account the teaching environment's requirements for network bandwidth and network speed, including coverage frequency, channel usage, and throughput requirements. Multiple APs are connected to a wired network through cables, allowing wireless terminals to access various parts of the network.
Normally, an AP can support the access of up to 80 computers. Of course, the workstation works best when the number is 20~30. The typical indoor coverage of the AP is 30~ 100m. Depending on the size of the classroom and conference hall, one or more wireless access points can be configured.
For example, 4 APs can be placed in a classroom (see attached picture), so that the classroom can accommodate up to 80 to 120 wireless network users.
2. Outdoor
Refers to campus playgrounds and other public places.
(1) Equipment selection: AP, wireless omnidirectional antenna, wireless directional antenna.
Omnidirectional antenna: The transmission and reception of signals are equal in all horizontal directions.
Directional antenna: transmits and receives most of the signal in one direction.
(2) Outdoor considerations
Different from classrooms and conference rooms, configuring wireless access points outdoors in the campus area is more complicated, and they must be integrated into a local area network. Buildings at a certain distance are connected. Connect an AP at each end of the network, and connect an external high-gain antenna in a place where the distance is far or where the signal is weak, so that the interconnection between two network segments within a few kilometers can be achieved.
In this plan, we set up an omnidirectional outdoor antenna and an outdoor directional antenna in the library (central computer room). The omnidirectional antenna covers all teaching buildings and playgrounds on campus; a set-directional antenna is installed in the laboratory building to transmit the signal to teaching building A; a set-directional antenna is also set up in teaching building A to transmit the signal to teaching building B; in the teaching building An omnidirectional antenna can be set up on B to cover the lawn and also transmit the signal to the teaching building C. Other buildings can be deduced in the same way.
During specific operations, the selection of equipment (such as equipment model, whether to add omnidirectional and directional antennas, and Increase or decrease the number of equipment, etc.).
Of course, when setting up wireless network equipment in a building, it is necessary to install lightning arresters, moisture-proof boxes and other equipment to prevent damage to the wireless network equipment.
Advantages of this solution
Only a wireless network card and an AP are needed to share network resources wirelessly with the existing wired architecture. WLAN has the advantages of convenient installation, flexible use, easy expansion, low price, and low radiation. It can quickly and conveniently solve network connectivity problems that are difficult to achieve using wired methods. In terms of security, the IEEE 802.11b standard can provide a confidentiality mechanism, and schools can also use some management policies (such as only authorized users can access wireless devices, etc.) and VPN (virtual private network) to enhance security performance.