KR101970158B1 - Method for Distributing Traffic on Secondary Channel First so as to Operate LTE-LAA and eNode-B Using the Method - Google Patents

Abstract

A base station apparatus for performing secondary channel priority traffic distribution method and method for LTE-LAA operation is disclosed. The traffic distribution of the present invention firstly distributes the LT traffic to the secondary channel, and distributes the traffic to the primary channel only when the traffic of the secondary channel becomes the preset maximum traffic. Thus, by securing priority traffic in a secondary channel having a traffic competition with another communication entity, it is possible to reserve a relatively stable primary channel as much as possible. Therefore, even if traffic demand increases, it is possible to handle stable LT traffic through the primary channel.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a secondary channel priority traffic distribution method and a base station apparatus for performing LTE-LAA operation,

The present invention relates to a traffic distribution method of a mobile communication base station for distributing traffic primarily between a primary channel and a secondary channel for LTE-LAA operation, and a base station apparatus performing the method.

Since the frequency resources are limited, the lack of frequency resources is already a normal situation. Currently, LTE (Long Term Evolution) mobile communication service uses so-called "license band" which is authorized as exclusive channel for LTE. However, since the traffic of mobile communication network continues to increase, Traffic becomes increasingly difficult to afford.

However, since it is necessary to pay a considerable fee to obtain a new frequency band as an additional license, efforts have been made to make use of the license-free band that can be used free of charge with mobile network equipment manufacturers of multinational companies. As a result, LTE-U (LTE-Unicensed Spectrum) and LTE-LAA (LTE-UA) that aggregate frequencies of license-denied and licensed bands under the name of Licensed-assisted Access (LAA) in 3rd Generation Partnership Project (3GPP) -Assisted Access) technology has been proposed. The problem is that the license-exempt band used by the LTE camp is 5 ㎓, which is already used by wi-fi.

The difference between LTE-U and LTE-LAA is to perform a Listen Before Talk (LBT) process, where LTE-LAA performs LBT. The LAA is a technology that bundles license and license-exempt bands into one using frequency aggregation technology, with the LTE license band as an anchor. In LTE-LAA, the terminal always uses the service by accessing the network with the licensed band, and instead, the base station combines the licensed band and the license-exempted band with the frequency aggregation technology to offload the traffic of the licensed band to the license- do. At this time, the license band is referred to as a primary band, and the license-exempt band is referred to as a secondary band. Even if the traffic is divided by offloading, the system control information is provided in the primary band, and only the user data is provided in the secondary band which is the license-exempt band.

Since LTE-LAA is a newly proposed and developing technology, there has never been proposed a traffic distribution technique for simultaneously operating licensed and license-exempt bands in LTE-LAA. LTE operators basically want to maximize the use of the primary band, which is allowed to use exclusively by allocating the maximum amount of traffic to the secondary band. However, since the secondary band is a license-exempt band that uses other wireless devices such as wi-fi, it has a disadvantage in that the channel state is not excellent. Therefore, the policy for proper distribution of the primary and secondary bands is more important than the operation of the LTE-LAA.

[Related Prior Art]

Korean Patent Publication No. 10-2016-0138556 (devices and methods for searching and using neighbor WLAN information for LTE LAA operation)

The present invention relates to a method for requesting and obtaining information on a license-exempt band from a terminal for LAA operation, and is not strictly related to the present invention.

It is an object of the present invention to provide a traffic distribution method for a mobile communication base station that distributes traffic primarily between primary and secondary channels for LTE-LAA operation, and a base station apparatus that performs the method. .

The mobile communication base station apparatus according to the present invention is connected to a mobile communication terminal through a primary channel and a secondary channel. The primary channel is a licensed band that is exclusively licensed for wireless channels in accordance with the LTE protocol, and the secondary channel is a license-exempt band that shares the frequency band with Wi-Fi. The traffic can be appropriately distributed between the primary channel and the secondary channel of the mobile communication base station apparatus of the present invention.

A method of distributing a traffic of a mobile communication base station apparatus includes the steps of: (a) requesting a new traffic demand; (b) distributing the new traffic through the secondary channel according to the new traffic demand, Increasing the LTE traffic (T ₂ ); and (c) repeating the step (b), terminating traffic distribution for the new traffic if the following equation is satisfied.

Here, T ₁ is the LTE traffic of the primary channel, and D is the total traffic demand including the new traffic.

인 상태에서 상기 세컨더리 채널의 LTE 트래픽(T₂)이 기설정된 세컨더리 채널 최대 트래픽(T_2max)에 도달하면, 상기 프라이머리 채널을 통해 상기 새로운 트래픽을 추가 분배하여 상기 프라이머리 채널의 LTE 트래픽(T₁)을 증가시킨다. According to an embodiment of the present invention, a method of distributing traffic of a mobile communication base station apparatus further includes the step (d). In the step (d), during the step (c)

, The LTE traffic (T ₂ ) of the secondary channel further distributes the new traffic through the primary channel to the LTE traffic (T _2max ) of the primary channel when the LTE traffic (T ₂ ) of the secondary channel reaches the predetermined secondary channel maximum traffic ₁ ).

According to another embodiment of the present invention, a method of distributing traffic of a mobile communication base station apparatus further comprises the step (e). In step (e), the step (d) is repeated until the following equation is satisfied: if the LTE traffic (T ₁ ) of the primary channel reaches the predetermined primary channel maximum traffic (T _1max ) And ends the additional distribution for the new traffic.

The present invention is also applicable to a mobile communication base station apparatus for distributing LT traffic by performing the above-described method when new traffic demand occurs.

The present invention proposes a method for effectively using both bands by LTE-LAA using both licensed and unlicensed bands.

The mobile communication system supporting the LTE-LAA according to the present invention allocates traffic primarily to the secondary channel, thereby maximizing the secondary channel required to compete with another communication entity (e.g., wifi in the 5 GHz band) to thereby obtain a relatively stable primary channel As much as possible. This can effectively use the primary channel for high traffic demand.

Therefore, when the traffic demand is small, the secondary channel is distributed first, and when the maximum traffic of the secondary channel is reached as the demand for traffic increases, the primary channel can be effectively distributed by distributing the secondary channel effectively.

FIG. 1 is a block diagram of a channel between a mobile communication base station and a mobile communication terminal according to the present invention.
FIG. 2 is a flowchart provided in the explanation of the traffic distribution method of the mobile communication base station of the present invention, and
3 is a graph showing the secondary channel preference distribution result of the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in more detail with reference to the drawings.

Referring to FIG. 1, the mobile communication base station apparatus 110 includes a primary channel 10, which is a license band, and a secondary channel 30, which is a license-exempt band. ).

Here, the primary channel 10 and the secondary channel 30 are classified in terms of the mobile communication base station apparatus 110, and the primary channel 10 is dedicated to a radio channel conforming to the LTE protocol And the secondary channel 30 is a radio channel using a frequency band that has never been authorized to be dedicated to a specific radio channel.

For example, the 5 GHz band belongs to the license-exempted band, and the following description will be made using the 5 GHz band as an example. Since the license-exempt band is not licensed to be used exclusively on a specific radio channel, other radio channels as well as mobile communications may be used. As described above, the 5 ㎓ band is already used by wi-fi.

The base station apparatus 110 transmits a data packet to the terminal 130 using one of the primary channel 10 and the secondary channel 30 according to a predetermined resource allocation policy. In this case, even if the secondary channel 30 is used, the system control information is still provided to the primary channel 10, and only the user data is provided to the secondary channel 30 which is the license-exempt band.

The base station apparatus 110 of the present invention may include an algorithm for distributing traffic to the primary channel 10 and the secondary channel 30 of the LAA and the algorithm or policy proposed by the present invention is a secondary channel priority policy.

For the determination of such a policy, the secondary of this invention, by setting each of the maximum traffic, the primary channels 10 and secondary channels (30), T _1max and T _2max, and the distribution to the maximum value of each traffic that requires traffic competition with wifi The channel can be preferentially used and the relatively stable primary channel can be reserved as much as possible.

Traffic distribution method

Hereinafter, a traffic distribution scheme proposed by the present invention will be described with reference to FIG. The present invention proposes a method of preferentially distributing traffic among the primary channel and the secondary channel among the secondary channels.

<Initiation of Traffic Distribution Algorithm According to Traffic Occurrence: S201, S203>

When a new traffic demand occurs (S201), the base station apparatus 110 tries to distribute the traffic to the secondary channel. As a result, the available traffic T ₂ of the secondary channel increases.

<Secondary channel traffic distribution until traffic demand is resolved: S205>

The base station apparatus 110 compares the sum of the available traffic T ₂ of the newly allocated secondary channel and the available traffic T ₁ of the existing primary channel with the currently requested total traffic demand D, It is determined whether the traffic demand D is large as in Equation (1).

Where D is the total traffic demand of the LAA, including new traffic demand. If the LAA traffic demand D corresponds to Equation 1 despite the traffic distribution in step S203, the flow returns to step S203 to further distribute the traffic to the secondary channel.

If the LAA traffic demand (D) results in the following Equation (2) as a traffic distribution in step S203, it means that it satisfies the current LAA traffic demand (D) as a result of traffic distribution to the secondary channel. And terminates.

&Lt; Traffic distribution to the primary channel when distributed to the maximum traffic of the secondary channel: S207 >

If it is determined in step S205 that the situation corresponds to Equation 1, the base station apparatus 110 determines whether the traffic distribution to the current secondary channel is distributed to the secondary channel maximum traffic ( _T2max ) before returning to step S203 (S207).

If the primary channel is divided by the secondary channel maximum traffic (T _2max ), the base station apparatus 110 starts distributing traffic to the primary channel (S 209).

The base station apparatus 110 may return to S205 step, the new distribution of traffic of the primary channel (T _1max), and the total traffic demand, the sum of the available traffic (T ₂₎ of the existing distribution secondary channel a current request (D) and Then, step S209 is repeated until Equation (2) is satisfied to further distribute the traffic to the primary channel.

<End of traffic distribution according to the secondary channel maximum traffic: S211>

After performing step S209 and before returning to step S205, the base station apparatus 110 first determines whether the traffic distribution to the primary channel is distributed to the primary channel maximum traffic (T _{1 max} ).

If the traffic is distributed up to the primary channel maximum traffic (T _{1 max} ), the traffic distribution is no longer allowed, so the base station apparatus 110 does not return to step S 205 and ends the distribution of the newly requested traffic.

In this way, the secondary channel preferential allocation method of the present invention is performed.

In general, the secondary channel must compete with another communication entity (for example, wifi), unlike the primary channel. Therefore, depending on the situation, the secondary channel may not be used as much as necessary. Given this, it may be advantageous to reserve primary traffic as much as possible by distributing priority traffic to the secondary channel when traffic is not yet high. If you have a lot of LT traffic, you can get priority service from the primary channel again.

The result of applying the distribution algorithm of FIG. 2 is shown in FIG. FIG. 3 shows an example in which the primary channel maximum traffic (T _{1 max} ) is set to 75, and the secondary channel maximum traffic (T 2 _max ) is set to 40. Therefore, traffic demand can be accommodated up to 115. If secondary channel traffic is distributed first and then secondary channel maximum traffic, it can be confirmed that traffic is distributed to the primary channel. In general, since the primary channel maximum traffic (T _1max) it is larger than the secondary peak traffic channel (T _2max), when the traffic demand 80 is the traffic volume of the primary distribution channel beyond the traffic amount of the secondary distribution channel.

If the demand for traffic is very small, the secondary channel is used first according to the influence of the policy factor. Primary channels are used only when there is more traffic than can be accommodated by a secondary channel.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is clearly understood that the same is by way of illustration and example only and is not to be construed as limiting the scope of the invention as defined by the appended claims. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention.

Claims (4)

A mobile communication base station apparatus connected to a mobile communication terminal through a secondary channel, which is a licensed band for exclusive use in a wireless channel according to the LTE protocol, and a secondary channel which is a license-exempt band sharing a frequency band with Wi-Fi A traffic distribution method comprising:
(a) requesting a new traffic demand;
(b) increasing the LTE traffic (T ₂ ) of the secondary channel by further distributing the new traffic through the secondary channel according to the new traffic demand; And
(c) repeating the step (b), the traffic distribution for the new traffic is terminated if the following equation is satisfied,

T ₁ is the LTE traffic of the primary channel, and D is the total traffic demand including the new traffic.
The method according to claim 1,
(d) during the step (c)

, The LTE traffic (T ₂ ) of the secondary channel reaches the predetermined secondary channel maximum traffic (T _1max ), the LTE traffic (T _1max ) of the primary channel is further distributed by distributing the new traffic through the primary channel ₁ ) to the mobile communication base station apparatus.
3. The method of claim 2,
(e) repeating step (d) until the following equation is satisfied,

Further comprising terminating further distribution to the new traffic when the LTE traffic (T ₁ ) of the primary channel reaches a preset primary channel maximum traffic (T _1max ) / RTI &gt;
A primary channel which is a licensed band for exclusive use in a wireless channel according to the LTE protocol, and a secondary channel which is a license-exempt band sharing a frequency band with Wi-Fi,
Wherein the traffic is distributed by performing the method according to any one of claims 1 to 3 when new traffic demand occurs.

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