1. Field of the Invention
The present disclosure relates to a method used in an access point in a wireless communication system, and more particularly, to a method of handover procedure for enhancing quality of wireless connection.
2. Description of the Prior Art
Conventional wireless communication standard IEEE 802.11 does not specify how a wireless station in a wireless local area network performs handover during roaming. Though the recent wireless communication standards, such as IEEE 802.11k and IEEE 802.11r, specify fast handover, pre-authentication, or handover assistant for better connection, the wireless station needs to actively perform handover. Otherwise, these mechanisms, i.e., fast handover, pre-authentication or handover assistant, will not be activated. In addition, based on the conventional handover process, sticky client problem occurs. In detail, the wireless station is roaming in an environment deployed with a plurality of access points, in which the wireless station is away from an original connected access point and approaches to another access point. In this situation, the wireless station continuously connects to the original access point and does not perform handover to the approached access point, which decreases a data rate of the wireless station and affects connection quality.
In the prior art, there is no solution for the sticky client problem. Unless the wireless station triggers the handover, the wireless station performs handover to connect with other access points only if it is far from the original access point and unable to receive wireless signal such that it disconnects with the original access point. For example, due to the unstable connection status, boundary client is in a position that a neighbor access point could be connected, but still transmits wireless packets to the original access point, which decrease transmission performance in the wireless environment.
It is therefore an objective to provide a method of handover to solve the sticky client problem and to enhance wireless performance efficiency.
The present disclosure provides a method for handover procedure enhancement performed by an access point (AP) in a wireless communication system. The method includes connecting to a mobile device in the wireless communication system; detecting a connection status with the mobile device; and determining whether to transmit a disconnection signal to the mobile device according to the connection status, in which the disconnection signal is configured to request the mobile device to perform a handover procedure.
The present disclosure further provides a method for handover procedure enhancement performed by an access point (AP) in a wireless communication system. The method includes receiving a packet from a mobile device in the wireless communication system, wherein the mobile device is connected to another AP in the wireless communication system, determining a connection information with the mobile device according to the received packet, and determining whether to transmit a disconnection signal to the mobile device according to the connection information, in which the disconnection signal is configured to request the mobile device to perform a handover procedure.
These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings.
Reference is made to
According to the process 20, the AP immediately detects and records the connection status (e.g., signal strength, transmission rate, transmission quality, packet missing ratio and channel occupancy time) with the wireless station after the wireless station connects to the AP, so as to determine distance and transmission quality between the wireless station and the AP. In other words, the AP can determine whether the wireless signal and communication quality with the wireless station is getting weak, to determine whether to send the disconnection message to the wireless station for requesting the wireless station to perform the handover procedure, such that the wireless station is able to connect to another AP.
Regarding the operation of the handover procedure, reference is made to
It should be noted that, an objective of the present disclosure is to solve the problem that the wireless station does not perform handover during roaming in a wireless environment deployed with multiple APs. With the triggering mechanism provided by the present disclosure, the AP can assist the wireless station to perform handover even within an environment in which APs are not produced by the same manufacturer, or the wireless station is a legacy client which does not support handover procedure of the new wireless communication protocol, such as IEEE 802.11K or 802.11R, so as to avoid sticky client problem which decreases wireless performance efficiency (e.g., low transmission rate, high packet loss ratio or long transmission chancel occupancy time).
Reference is made to
According to the process 40, when connecting to the AP, the wireless station broadcasts connection packet and data packet on a channel corresponding to the AP, and thus the neighbor AP without connection to the wireless station obtains connection information (i.e., distance or signal strength) based on the broadcasted packet. In other words, the neighbor AP determines whether to send a disconnection message, for requesting the wireless station to handover to other AP, according to the distance and signal strength with the wireless station, to prevent the wireless station continuously connecting to the original AP. For example, after the neighbor AP analyzes connection information of the packet, and knows that the signal strength is higher than a threshold or that the wireless station is roaming around, the neighbor AP transmits a disconnection signal to the wireless station, to force the wireless station handover to another AP, in which the connection quality between the another AP and the wireless station is better than the original one.
Reference is made back to
Based on those mentioned above, a software manner is adapted for the AP to monitor the wireless station, to analyze the information in the packet received from the wireless station and knows that the wireless station is roaming to a proper place for handover. Thus, the AP can assist the wireless station to handover to another AP, so as to decrease a number of sticky clients and enhance efficiency of the wireless communication system. In addition, by triggering handover via the AP, legacy clients, which do not support latest handover procedure, sticky clients, and boundary clients can handover to a AP with stronger wireless signal as soon as possible, so as to improve the wireless performance. In other words, instead of performing handover until disconnection occurs, the AP forces the wireless station to perform handover procedure at a proper time. Therefore, the roaming wireless station performs handover accordingly, so as to solve the problem of boundary client unstable connection.
On the other hand, reference is made to
In conclusion, the present disclosure provides a method for the AP to request the roaming wireless station to disconnect with the AP, and further assist the wireless station to perform the handover to connect to a better AP. As such, the problem of sticky client away from the AP but still connecting to the AP is solved with the present invention, so as to avoid decreasing connection quality and affecting wireless performance.
Those skilled in the art will readily observe that numerous modifications and alterations of the device and method may be made while retaining the teachings of the invention. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims.
Number | Date | Country | Kind |
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105107452 | Mar 2016 | TW | national |