WO2009041754A1

WO2009041754A1 - Network configuration method for future wireless communication system

Info

Publication number: WO2009041754A1
Application number: PCT/KR2008/000660
Authority: WO
Inventors: Dong Ho Cho; Ho Won Lee; O Hyun Jo; Woong Sup Lee; Hee Jung Yu; Young Seok Oh; Yong Hoon Lee
Original assignee: Korea Advanced Institute Of Science And Technology
Priority date: 2007-09-28
Filing date: 2008-02-04
Publication date: 2009-04-02
Also published as: KR20090032544A; KR100945879B1

Abstract

The present invention relates to a method of configuring outdoor and indoor networks in the next generation mobile communication system and a method of selecting a transmission frequency for optimal service according to the situation of a user terminal in the outdoor and indoor networks. The method of configuring a network and selecting a transmission frequency in the next generation mobile communication system according to the present invention is configured such that, in the next generation mobile communication system, including a base station controller and a base station, the base station and the base station controller perform wireless communication in a licensed band from 60 to 70 GHz. Furthermore, the base station and a user terminal are configured to perform wireless communication at frequencies allocated according to the mobility characteristics of the user terminal and information about whether a LOS channel has been guaranteed.

Description

NETWORK CONFIGURATION METHOD FOR FUTURE WIRELESS COMMUNICATION SYSTEM

Technical Field

[1] The present invention relates to a method of configuring outdoor and indoor networks in a next generation mobile communication system. The method selects a transmission frequency for optimal service according to the situation of a user terminal in the outdoor and indoor networks. Background Art

[2] In the existing second-generation system and the third-generation mobile communication system, a method of configuring a network is not differentiated between outdoor and indoor areas and is uniformly designated, so that high-quality service cannot be dynamically supported to a user depending on the situation.

[3] FIG. 1 is a diagram showing the configuration of conventional outdoor and indoor networks. In conventional outdoor network, a Base station is connected to a backhaul in a wired manner. That is, a base Station Controller (BSC), configuring and managing a single outdoor network, is connected to the backhaul in a wired manner. A link between a Base Station (BS), configuring and managing a single cell, and the BSC, and links between BSs are also established through wired connections. Further, a link between a BS and a terminal is established through a wireless link with licensed frequencies. Since such an outdoor environment must support users within a wide coverage using higher power, an interference problem is important. Therefore, in order to prevent the influence of interference on other systems, the outdoor environment uses licensed frequencies having an exclusive right for the use of the frequencies.

[4] Meanwhile, in an existing indoor environment, an Access Point (AP) is configured to be connected to a backhaul in a wired manner. That is, an Access Point Controller (APC), configuring and managing a single indoor network, is connected to a backhaul in a wired manner. A link between an AP, configuring and managing a single indoor cell, and an APC is also established through a wired connection. Further, the link between the AP and a terminal is established through a wireless connection in an unlicensed band.

[5] Generally, an indoor network is used in a manner such that frequencies are shared with other users in an unlicensed band that can be used in common, like an Industrial/ Scientific/Medical (ISM) band. In the case of local area communication, since there is no need to cover a wide area, and the range of interference is small. Then, costs can be reduced and high transmission capacity can be obtained in local area communication through the use of an unlicensed band.

[6] In summary, a single Base Station (BS) manages a single cell in an outdoor environment, and a Base Station Controller (BSC) is a controller for managing all BSs included in a single network. Further, a single Access Point (AP) manages a single cell in an indoor environment, and an Access Point Controller (APC) is a controller for managing all APs included in a single network.

[7] In the prior art, the link between a BSC and a BS, the link between BSs, and the link between an APC and an AP are established through a wired connection, and thus the network is configured. However, in this case, the costs required to construct an infrastructure and configure a network are greatly increased. In particular, high frequencies must be used to cover a wide bandwidth and support high cell capacity in a wireless link. When high frequencies are used, the propagation characteristics of signals are deteriorated, so that it is impossible to cover a wide area, and thus the size of cells is inevitably reduced. This results in the problem in which a large number of base stations or access points must be installed. As the number of Base Stations (BSs) or Access Points (APs) increases in this way, the cost required for the configuration of a network increases drastically.

[8] Further, since a wireless link between a BS and a terminal and a wireless link between an AP and a terminal use limited bandwidth at licensed frequencies, the increase in cell capacity is limited. That is, in the prior art, since usable bandwidths for respective systems are given in a licensed band, and there is no method of configuring a network using both a licensed band and an unlicensed band, and selecting a transmission frequency, it is difficult to efficiently utilize frequency resources in actual situations. Further, there is no method of providing optimized services to users according to the situations of user terminals because the network configuration method is not differentiated between an outdoor network and an indoor network. Disclosure of Invention Technical Problem

[9] Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and an object of the present invention is to provide a method of configuring a network and selecting a transmission frequency in the next generation mobile communication system, which can configure outdoor and indoor networks optimized for the situations of respective users in consideration of the users situations and can support flexible services in the next generation mobile communication system, in which various environments coexist. Technical Solution

[10] In order to accomplish the above object, the present invention provides a method of configuring a network and selecting a transmission frequency in a next generation mobile communication system, the system including a base station controller and a base station, wherein the base station and the base station controller perform wireless communication in a licensed band from 60 to 70GHz.

[11] Further, the present invention provides a method of configuring a network and selecting a transmission frequency in a next generation mobile communication system, the system including a base station and a user terminal, wherein the base station and the user terminal perform wireless communication at frequencies allocated according to mobility characteristics of the user terminal and information about whether a Line of Sight (LOS) channel has been guaranteed. Further, if the user terminal is that of a moving user, a base station or a relay node is deployed on a roadside along which the moving user is moving.

[12] Further, the present invention provides a method of configuring a network and selecting a transmission frequency in a next generation mobile communication system, the system including a backhaul, an access point controller, and an access point, wherein the backhaul and the access point controller perform wireless communication in a licensed band from 60 to 70GHz.

[13] Further, the present invention provides a method of configuring a network and selecting a transmission frequency in a next generation mobile communication system, the system including an access point controller and an access point, wherein the access point controller and the access point perform wireless communication in a licensed band from 60 to 70GHz.

[14] In addition, the present invention provides a method of configuring a network and selecting a transmission frequency in a next generation mobile communication system, the system including an access point and a user terminal, wherein the access point and the user terminal perform wireless communication at frequencies allocated according to whether a LOS channel with the user terminal has been guaranteed and whether network capacity is intended to be increased.

Advantageous Effects

[15] According to the present invention, wireless resources in an ultra-high frequency band can be efficiently used so as to perform communication for a link between a base station and a base station controller and a link between base stations in an outdoor network, so that a wired connection is replaced with a wireless connection, thus greatly reducing infrastructure construction costs required to configure a network. Further, the present invention allocates frequencies according to the situation of an outdoor user terminal, thus improving efficiency of resource use.

[16] Furthermore, according to the present invention, wireless resources in an ultra-high frequency band can be efficiently used so as to perform communication for a link between an access point controller and an access point in an indoor network, so that a wired connection is replaced with a wireless connection, thus greatly reducing the infrastructure construction costs required to configure a network. Further, the present invention allocates frequencies according to the situation of an indoor user terminal, thus improving efficiency of resource use. Brief Description of the Drawings

[17] FIG. 1 is a diagram showing the configuration of conventional outdoor and indoor networks;

[18] FIG. 2 is a flowchart showing a method of configuring an outdoor network and sele cting a transmission frequency in the base station of the next generation mobile communication system according to the present invention;

[19] FIG. 3 is a flowchart showing a method of configuring an indoor network and selecting a transmission frequency in the access point of the next generation mobile communication system according to the present invention; and

[20] FIG. 4 is a diagram showing the configuration of the entire network according to the present invention. Best Mode for Carrying Out the Invention

[21] The present invention proposes a method of configuring a network and allocating a frequency according to the situation of a user terminal in the next generation mobile communication system. The configuration of networks is based on classifying network environments into an outdoor environment and an indoor environment. Mode for the Invention

[22] First, an outdoor environment is described.

[23] When users in an outdoor environment are classified according to mobility characteristics, they are divided into moving users, having high mobility, and nomadic users, having low mobility. Further, the wireless channel of an outdoor environment can be classified into the case where a Line of Sight (LOS) channel with a base station is guaranteed (LOS case) and the case where a LOS channel is not guaranteed (Non Line of Sight NLOS case).

[24] FIG. 2 is a flowchart showing a method of configuring an outdoor network and selecting a transmission frequency in the base station of the next generation mobile communication system according to the present invention.

[25] Generally, since both a base station controller and base stations are deployed in a high area, LOS channels are guaranteed for the links between the base station controller and base stations and links between respective base stations. Each of the base stations determines a communication target at step S21. When the communication target is the base station controller or another base station, a high-frequency wide band corresponding to a licensed band from 60 to 70 GHz is allocated for the link, and thus communication is performed in a wireless manner at step S22.

[26] In this way, when wireless communication is performed between the base station and the base station controller, and between respective base stations, there is a problem in that the propagation characteristics are deteriorated due to the high frequency band, but this problem can be solved by way of a multiple access method using beamforming based on array antennas.

[27] Further, when the communication target is a user terminal at step S21, the base station performs communication by allocating different frequencies according to the degree of mobility of the user terminal and information about whether a LOS channel with the base station has been guaranteed. First, the base station determines the mobility characteristics of the user terminal at step S23. When the user terminal is that of a nomadic user having low mobility, the base station determines whether a LOS channel has been guaranteed at step S24. If it is determined at step S24 that a LOS channel has been guaranteed, a high-frequency wide band corresponding to a licensed band from 60 to 70 GHz is allocated to a communication link to the user terminal, as in the case of the link between base stations, in order to improve transmission capacity using wide bandwidth in high frequency at step S25. However, if it is determined at step S24 that a LOS channel has not been guaranteed, the base station determines whether a LOS channel can be guaranteed through a relay node at step S26. If it is determined that a LOS channel can be guaranteed through the relay node, the process proceeds to step S25, at which a high-frequency wide band corresponding to a licensed band from 60 to 70 GHz is allocated to the communication link to the user terminal. If it is determined at step S26 that a LOS channel cannot be guaranteed through a relay node, a low frequency band from several hundred MHz to several GHz is allocated to the communication link to the user terminal at step S27. When a low frequency band is used in this way, propagation characteristics are greatly improved, and thus efficient communication is possible even if a LOS channel is not guaranteed.

[28] Meanwhile, even when the user terminal is that of a moving user having high mobility, such as one installed in a vehicle, at step S23, the base station determines once whether a LOS channel has been guaranteed at step S28. If it is determined that the LOS channel has been guaranteed, the movement speed of the user terminal is detected at step S29, and different frequency bands are allocated to the user terminal according to the movement speed. When the user terminal is moving at high speed, that is, a speed equal to or greater than a threshold value, a low frequency band from several hundred MHz to several GHz is allocated at step S30. When the user terminal is moving at low speed, that is, a speed less than the threshold value, a high frequency band corresponding to a licensed band from 60 to 70 GHz is allocated at step S31. Further, even when a LOS channel is not guaranteed at step S28, the process proceeds to step S30, at which a low frequency band from several hundred MHz to several GHz is allocated.

[29] In the case of a moving user terminal having high mobility, such as one installed in a vehicle, since it is difficult to implement technology using beamforming based on an array antenna, like the configuration of the network between base stations or between each base station and a base station controller, a network using Multiple-In Multiple- Out (MIMO) technology based on channel feedback is configured, and thus the moving user is supported.

[30] Further, since most moving users having high mobility move along a designated path, as in the case of a vehicle or a train, a base station or a relay node is installed on the roadside, thus enabling a network to be efficiently configured at a minimum of expense. An example of the base station or the relay node installed on the roadside, a base station or a relay node can be installed on facilities used in a traffic system, such as a streetlamp or a signal lamp installed on the roadside. Through the base station or the relay node, large-capacity service content can be supported at high speed, and most movement areas can be covered.

[31] Hereinafter, the case of an indoor environment is described below.

[32] When user terminals in an indoor environment are classified according to their mobility characteristics, they are divided into fixed users, having no mobility, and nomadic users, having low mobility. That is, since there is no user terminal having high mobility in a limited indoor space, the configuration of a network for moving users is not considered. In an indoor environment, a method of configuring a network from an Access Point Controller (APC) to a backhaul, a method of configuring the network between an Access Point (AP) and the APC, and a method of configuring the network between a fixed user or a nomadic user and an AP are proposed.

[33] First, in the configuration of the network between the APC and the backhaul, the

APC can be connected to the backhaul in a wired manner, similar to the prior art. When a LOS channel is guaranteed between the APC and the backhaul, a licensed band from 60 to 70 GHz can be allocated. When high-frequency wideband communication using a band from 60 to 70 GHz is performed between the APC and the backhaul in this way, there is a problem in that propagation characteristics are deteriorated due to the high frequency band, but this problem can be solved using beamforming based on array antennas.

[34] FIG. 3 is a flowchart showing a method of configuring an indoor network and selecting a transmission frequency in the access point of the next generation mobile communication system according to the present invention. [35] In the method of configuring the network between an APC and an AP, the APC and the AP can be connected to each other in a wired manner, similar to the prior art. When a LOS channel is guaranteed between the APC and the AP, an unlicensed band from 60 to 70 GHz can be allocated.

[36] That is, the AP determines a communication target at step S41. When the communication target is an APC, an unlicensed band from 60 to 70 GHz is allocated at step S42.

[37] Meanwhile, the channel of the network between an AP and a user terminal can be classified into the case where a LOS channel is guaranteed and the case where a LOS channel is not guaranteed.

[38] When the communication target is a user terminal, the AP determines whether a LOS channel has been guaranteed at step S43. If it is determined that a LOS channel has been guaranteed, and network capacity is intended to be increased at step S44, an unlicensed band from 60 to 70 GHz is allocated at step S45. When the LOS channel is determined to be guaranteed, and there is no need to increase network capacity at step S44, an unlicensed Industrial/Scientific/Medical (ISM) band is allocated, as in the case of a Wireless Local Area Network (WLAN), at step S46. When an unlicensed band from 60 to 70 GHz is allocated at step S45, a network having higher capacity and higher flexibility can be configured. In contrast, if it is determined that a LOS channel has not been guaranteed at step S43, it is difficult to use high frequencies in the current situation, and thus indoor local area communication is performed using the unlicensed ISM band at step S46.

[39] FIG. 4 is a diagram showing the configuration of the entire network according to the present invention.

[40] Although the technology of the present invention has been disclosed with reference to the attached drawings, this is not intended to limit the present invention, but is intended to exemplify the preferred embodiments of the present invention. Further, those skilled in the art will appreciate that various modifications and substitutions are possible, without departing from the scope and spirit of the invention. Industrial Applicability

[41] The present invention can be utilized to construct the infrastructure of a next generation mobile communication system.

[42]

Claims

[1] A method of configuring a network and selecting a transmission frequency in a next generation mobile communication system, the system including a base station controller and a base station, wherein: the base station and the base station controller perform wireless communication in a licensed band from 60 to 70GHz.

[2] The method according to claim 1, wherein the base station and the base station controller perform communication in a multiple access method using beamforming based on array antennas.

[3] A method of configuring a network and selecting a transmission frequency in a next generation mobile communication system, the system including a base station and a user terminal, wherein: the base station and the user terminal perform wireless communication at frequencies allocated according to mobility characteristics of the user terminal and information about whether a Line of Sight (LOS) channel has been guaranteed.

[4] The method according to claim 3, wherein, if the user terminal is that of a nomadic user, and a LOS channel has been guaranteed, frequencies in a licensed band from 60 to 70 GHz are allocated to the user terminal.

[5] The method according to claim 3, wherein, if the user terminal is that of a nomadic user, and a LOS channel has been guaranteed through a relay node, frequencies in a licensed band from 60 to 70 GHz are allocated to the user terminal.

[6] The method according to claim 3, wherein, if the user terminal is that of a nomadic user, and a LOS channel has not been guaranteed, low frequencies from several hundred MHz to several GHz are allocated to the user terminal.

[7] The method according to claim 3, wherein, if the user terminal is that of a moving user that is moving at high speed, that is, a speed equal to or greater than a threshold value, and if a LOS channel has been guaranteed, low frequencies from several hundred MHz to several GHz are allocated to the user terminal.

[8] The method according to claim 3, wherein, if the user terminal is that of a moving user that is moving at low speed, that is, a speed less than the threshold value, and if a LOS channel has been guaranteed, frequencies in a licensed band from 60 to 70 GHz are allocated to the user terminal.

[9] The method according to claim 8, wherein the base station and the user terminal perform communication using Multiple-In Multiple- Out (MIMO) technology based on channel feedback. [10] The method according to claim 3, wherein, if the user terminal is that of a moving user, and a LOS channel has not been guaranteed, low frequencies from several hundred MHz to several GHz are allocated to the user terminal. [11] The method according to any of claims 7 to 10, wherein a base station or a relay node is deployed on a roadside along which the moving user is moving. [12] A method of configuring a network and selecting a transmission frequency in a next generation mobile communication system, the system including a backhaul, an access point controller, and an access point, wherein: the backhaul and the access point controller perform wireless communication in a licensed band from 60 to 70GHz. [13] The method according to claim 12, wherein the backhaul and the access point controller perform communication in a multiple access method using beamforming based on array antennas. [14] A method of configuring a network and selecting a transmission frequency in a next generation mobile communication system, the system including an access point controller and an access point, wherein: the access point controller and the access point perform wireless communication in a licensed band from 60 to 70GHz. [15] The method according to claim 14, wherein the access point controller and the access point perform communication in a multiple access method using beamforming based on array antennas. [16] A method of configuring a network and selecting a transmission frequency in a next generation mobile communication system, the system including an access point and a user terminal, wherein: the access point and the user terminal perform wireless communication at frequencies allocated according to whether a LOS channel with the user terminal has been guaranteed and whether network capacity is intended to be increased. [17] The method according to claim 16, wherein, if the LOS channel with the user terminal has been guaranteed, and network capacity is intended to be increased, frequencies in a unlicensed band from 60 to 70 GHz are allocated to the user terminal. [18] The method according to claim 16, wherein, if the LOS channel with the user terminal has been guaranteed, and network capacity is not intended to be increased, frequencies in an unlicensed Industrial/Scientific/Medical (ISM) band are allocated to the user terminal. [19] The method according to claim 16, wherein, if the LOS channel with the user terminal has not been guaranteed, frequencies in an unlicensed ISM band are allocated to the user terminal.