Base station device and radio communication system and frequency allocation method
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15 claims: 7 independent, 8 dependent
- 1複数の移動局と通信可能な基地局装置において、 自装置に優先的に割り当てられた第1周波数帯域を使用して少なくとも1つの移動局と通信を行う少なくとも1つの第1の無線通信回路と、 自装置以外に優先的に割り当てられた複数の第2周波数帯域の少なくとも1つを使用して少なくとも1つの移動局と通信を行う複数の第2の無線通信回路と、 前記複数の第2の無線通信回路における前記複数の第2周波数帯域の電力を定期的に検出して、前記複数の第2周波数帯域の使用有無を検出する周波数検出手段と、 前記周波数検出手段で検出された前記複数の第2周波数帯域の使用有無が履歴として記憶される周波数検出結果記憶手段と、 前記複数の移動局の通信中の単位時間あたりの情報データの平均通信頻度が当該移動局のIDと対応付けて記憶される通信状態記憶手段と、 前記周波数検出結果記憶手段を参照して過去N回の使用有無の検出結果から使用されていない未使用第2周波数帯域が存在すると判断し、かつ前記通信状態記憶手段を参照して前記第1周波数帯域を使用して通信中の移動局の前記平均通信頻度が一定値以下であると判断した場合、前記移動局との通信を前記第1周波数帯域から前記未使用第2周波数帯域へ変更する周波数変更制御手段と を備えることを特徴とする基地局装置。
- 2複数の移動局と通信可能な基地局装置において、 自装置に優先的に割り当てられた第1周波数帯域を使用して少なくとも1つの移動局と通信を行う少なくとも1つの第1の無線通信回路と、 自装置以外に優先的に割り当てられた複数の第2周波数帯域の少なくとも1つを使用して少なくとも1つの移動局と通信を行う複数の第2の無線通信回路と、 前記複数の第2の無線通信回路における前記複数の第2周波数帯域の電力を定期的に検出して、前記複数の第2周波数帯域の使用有無を検出する周波数検出手段と、 前記周波数検出手段で検出された前記複数の第2周波数帯域の使用有無が履歴として記憶される周波数検出結果記憶手段と、 前記複数の移動局の通信中の単位時間あたりの情報データの平均通信頻度及び前記情報データの単位回数あたりの平均データ長が当該移動局のIDと対応付けて記憶される通信状態記憶手段と、 前記周波数検出結果記憶手段を参照して過去N回の使用有無の検出結果から使用されていない未使用第2周波数帯域が存在すると判断し、前記通信状態記憶手段を参照して前記第1周波数帯域を使用して通信中の移動局の前記平均通信頻度が一定値以上であり、かつ前記平均データ長が一定値以下であると判断した場合、前記移動局との通信を前記第1周波数帯域から前記未使用第2周波数帯域へ変更する周波数変更制御手段と を備えることを特徴とする基地局装置。
- 3前記周波数変更制御手段は、前記未使用第2周波数帯域が複数存在した場合、当該第2周波数帯域の中から前記第1周波数帯域に近い帯域の未使用第2周波数帯域を選択して変更することを特徴とする請求項1又は請求項2のいずれかに記載の基地局装置。
- 4前記周波数変更制御手段は、前記複数の第2周波数帯域の周波数帯域幅がそれぞれ異なり、かつ前記未使用第2周波数帯域が複数存在した場合、当該第2周波数帯域の中から最も帯域幅が狭い未使用第2周波数帯域を選択して変更することを特徴とする請求項1又は請求項2のいずれかに記載の基地局装置。
- 5複数の移動局と通信可能な基地局装置において、 自装置に優先的に割り当てられた第1周波数帯域を使用して少なくとも1つの移動局と通信を行う少なくとも1つの第1の無線通信回路と、 自装置以外に優先的に割り当てられた複数の第2周波数帯域の少なくとも1つを使用して少なくとも1つの移動局と通信を行う複数の第2の無線通信回路と、 前記複数の第2の無線通信回路における前記複数の第2周波数帯域の電力を定期的に検出して、前記複数の第2周波数帯域の使用有無を検出する周波数検出手段と、 前記周波数検出手段で検出された前記第2周波数帯域の使用有無が履歴として記憶される周波数検出結果記憶手段と、 前記複数の移動局の通信中の単位時間あたりの情報データの平均通信頻度及び前記情報データの単位回数あたりの平均データ長が当該移動局のIDと対応付けて記憶される通信状態記憶手段と、 前記周波数検出結果記憶手段を参照して過去N回の使用有無の検出結果から使用されていない未使用第2周波数帯域が複数存在すると判断し、前記通信状態記憶手段を参照して前記第1周波数帯域を使用して通信中の移動局の前記平均通信頻度が一定値以上であり、かつ前記平均データ長が一定値以上であると判断した場合、前記移動局との通信を前記第1周波数帯域から前記複数の未使用第2周波数帯域の中から最も帯域幅が広い未使用第2周波数帯域へ変更する周波数変更制御手段と を備えることを特徴とする基地局装置。
- 6前記通信状態記憶手段に記憶された前記平均通信頻度及び前記平均データ長をもとに、前記第1周波数帯域の利用効率を算出する周波数利用効率評価手段をさらに備え、 前記周波数変更制御手段は、前記周波数利用効率評価手段が算出した前記利用効率が一定値 以上 と判断した場合、前記第1周波数帯域を使用して通信中の少なくとも1つの移動局との通信を前記第1周波数帯域から前記未使用第2周波数帯域へ変更することを特徴とする請求項1又は請求項2又は請求項5のいずれかに記載の基地局装置。
- 7前記周波数変更制御手段は、前記周波数利用効率評価手段が算出した前記利用効率が一定値 より小さい と判断した場合、前記移動局との通信を前記未使用第2周波数帯域から前記第1周波数帯域へ戻すことを特徴とする請求項6に記載の基地局装置。
- 8前記第1周波数帯域を使用して通信中の移動局の数をカウントする周波数利用効率評価手段をさらに備え、 前記周波数変更制御手段は、前記周波数利用効率評価手段がカウントした前記移動局の数が一定値 以上 と判断した場合、前記第1周波数帯域を使用して通信中の少なくとも1つの移動局との通信を前記第1周波数帯域から前記未使用第2周波数帯域へ変更することを特徴とする請求項1又は請求項2又は請求項5のいずれかに記載の基地局装置。
- 9前記周波数変更制御手段は、前記周波数利用効率評価手段が算出した移動局の数が一定値 より小さい と判断した場合、前記移動局との通信を前記未使用第2周波数帯域から前記第1周波数帯域へ戻すことを特徴とする請求項8に記載の基地局装置。
- 10前記通信状態記憶手段は、前記複数の移動局の通信待ち頻度を当該移動局のIDと対応付けてさらに記憶し、 前記通信状態記憶手段に記憶された前記通信待ち頻度の合計を算出する周波数利用効率評価手段をさらに備え、 前記周波数変更制御手段は、前記周波数利用効率評価手段が算出した前記通信待ち頻度の合計が一定値 以上 と判断した場合、前記第1周波数帯域を使用して通信中の少なくとも1つの移動局との通信を前記第1周波数帯域から前記未使用第2周波数帯域へ変更することを特徴とする請求項1又は請求項2又は請求項5のいずれかに記載の基地局装置。
- 11前記周波数変更制御手段は、前記周波数利用効率評価手段が算出した通信待ち頻度の合計が一定値 より小さい と判断した場合、前記移動局との通信を前記未使用第2周波数帯域から前記第1周波数帯域へ戻すことを特徴とする請求項10に記載の基地局装置。
- 12複数の移動局と、前記移動局の少なくとも1つと通信を行う基地局装置とを備え、 前記移動局は、 前記基地局装置に優先的に割り当てられた第1周波数帯域を使用して前記基地局装置と通信を行う第1の移動局側無線通信回路と、 前記基地局装置以外に優先的に割り当てられた複数の第2周波数帯域の少なくとも1つを使用して前記基地局装置と通信を行う第2の移動局側無線通信回路とを備え 前記基地局装置は、 前記第1周波数帯域を使用して前記移動局の前記第1の移動局側無線通信回路と通信を行う第1の基地局側無線通信回路と、 前記複数の第2周波数帯域の少なくとも1つを使用して前記移動局の前記第2の移動局側無線通信回路と通信を行う複数の第2の基地局側無線通信回路と、 前記複数の第2の基地局側無線通信回路における前記複数の第2周波数帯域の電力を定期的に検出して、前記複数の第2周波数帯域の使用有無を検出する周波数検出手段と、 前記周波数検出手段で検出された前記複数の第2周波数帯域の使用有無が履歴として記憶される周波数検出結果記憶手段と、 前記複数の移動局の単位時間あたりの情報データの平均通信頻度が当該移動局のIDと対応付けて記憶される通信状態記憶手段と、 前記周波数検出記憶手段を参照して過去N回の使用有無の検出結果から通信に使用されていない未使用第2周波数帯域が存在すると判断し、かつ前記通信状態記憶手段を参照して前記第1周波数帯域を使用して通信中の前記平均通信頻度が一定値以下であると判断した場合、前記移動局との通信を前記第1周波数帯域から前記未使用第2周波数帯域へ変更する周波数変更制御手段とを備える ことを特徴とする無線通信システム。
- 13複数の移動局と、前記移動局の少なくとも1つと通信を行う基地局装置とを備え、 前記移動局は、 前記基地局装置に優先的に割り当てられた第1周波数帯域を使用して前記基地局装置と通信を行う第1の移動局側無線通信回路と、 前記基地局装置以外に優先的に割り当てられた複数の第2周波数帯域の少なくとも1つを使用して前記基地局装置と通信を行う第2の移動局側無線通信回路とを備え 前記基地局装置は、 前記第1周波数帯域を使用して前記移動局の前記第1の移動局側無線通信回路と通信を行う第1の基地局側無線通信回路と、 前記複数の第2周波数帯域の少なくとも1つを使用して前記移動局の前記第2の移動局側無線通信回路と通信を行う複数の第2の基地局側無線通信回路と、 前記複数の第2の基地局側無線通信回路における前記複数の第2周波数帯域の電力を定期的に検出して、前記複数の第2周波数帯域の使用有無を検出する周波数検出手段と、 前記周波数検出手段で検出された前記複数の第2周波数帯域の使用有無が履歴として記憶される周波数検出結果記憶手段と、 前記複数の移動局の単位時間あたりの情報データの平均通信頻度及び前記情報データの単位回数あたりの平均データ長が当該移動局のIDと対応付けて記憶される通信状態記憶手段と、 前記周波数検出記憶手段を参照して過去N回の使用有無の検出結果から通信に使用されていない未使用第2周波数帯域が存在すると判断し、前記通信状態記憶手段を参照して前記第1周波数帯域を使用して通信中の移動局の前記平均通信頻度が一定値以上であり、かつ前記平均データ長が一定値以下であると判断した場合、前記移動局との通信を前記第1周波数帯域から前記未使用第2周波数帯域へ変更する周波数変更手段とを備える ことを特徴とする無線通信システム。
- 14基地局装置と少なくとも1つの移動局との間で前記基地局装置に優先的に割り当てられた第1周波数帯域を使用して通信中に、前記基地局装置以外に優先的に割り当てられた複数の第2周波数帯域から未使用第2周波数帯域を検出して割り当てを変更する方法であって、 前記複数の第2周波数帯域の電力を定期的に検出して前記複数の第2周波数帯域の使用有無を検出し、 検出した前記複数の第2周波数帯域の使用有無を履歴として周波数検出結果記憶手段に記憶し、 前記移動局の単位時間あたりの情報データの平均通信頻度を算出し、 前記周波数検出結果記憶手段を参照して過去N回の使用有無の検出結果から通信に使用されていない前記未使用第2周波数帯域を検出し、かつ前記第1周波数帯域を使用して通信中の移動局の前記平均通信頻度が一定値以下である場合、前記移動局との通信に使用する周波数帯域を前記第1周波数帯域から前記未使用第2周波数帯域に変更する ことを特徴とする周波数割当方法。
- 15基地局装置と少なくとも1つの移動局との間で前記基地局装置に優先的に割り当てられた第1周波数帯域を使用して通信中に、前記基地局装置以外に優先的に割り当てられた複数の第2周波数帯域から未使用第2周波数帯域を検出して割り当てを変更する方法であって、 前記複数の第2周波数帯域の電力を定期的に検出して前記複数の第2周波数帯域の使用有無を検出し、 検出した前記複数の第2周波数帯域の使用有無を履歴として周波数検出結果記憶手段に記憶し、 前記移動局の単位時間あたりの情報データの平均通信頻度及び前記情報データの単位回数あたりの平均データ長を算出し、 前記周波数検出結果記憶手段を参照して過去N回の使用有無の検出結果から通信に使用されていない前記未使用第2周波数帯域を検出し、前記第1周波数帯域を使用して通信中の第1の移動局の前記平均通信頻度が一定値以上であり、かつ前記平均データ長が一定値以下である場合、前記移動局との通信に使用する周波数帯域を前記第1周波数帯域から前記未使用第2周波数帯域に変更する ことを特徴とする周波数割当方法。
Independent claims15
87 paragraphs, as filed
The present invention relates to a base station apparatus, a wireless communication system, and a frequency allocation method.
In the conventional wireless communication system, a frequency band that can be used for each of the plurality of wireless communication systems is assigned in advance, and each wireless communication system realizes wireless communication using the assigned frequency band. However, the number of users of wireless communication systems is steadily increasing at present, and it is becoming difficult to cope with the increase in users only with the allocated frequency band.
As an efficient method of using frequencies under such circumstances, a plurality of wireless communication systems have a dedicated frequency band assigned to them and share a frequency band different from this dedicated frequency band among a plurality of systems. There is a method of improving the frequency utilization efficiency by doing so (see, for example, Patent Document 1).
That is, in Patent Document 1, the wireless communication system A in which the amount of communication traffic in the dedicated frequency band is increased requests the other wireless communication system B using the shared frequency band to use the shared frequency band. The other wireless communication system B that receives the request surrenders the shared frequency band to the wireless communication system A if the amount of communication traffic in its own dedicated frequency band is small.
In this way, the plurality of wireless communication systems use the shared frequency band efficiently according to the amount of communication traffic in their own dedicated frequency band.<patcit num="1"><text>Japanese Patent Application Laid-Open No. 2003-333648 (pages 16-18, Fig. 5)</text></patcit>
<p> However, in the invention described in Patent Document 1 described above, when the amount of communication traffic in the dedicated frequency band of the wireless communication system B using the shared frequency band is large, the wireless communication system B does not surrender the shared frequency band. Radio communication system A cannot use the shared frequency band. As described above, when the communication traffic volume of the plurality of wireless communication systems increases, there is a problem that the throughput of the wireless communication system that cannot use the shared frequency band is lowered and the communication request is rejected. Furthermore, even if the wireless communication system A uses the shared frequency band, if the amount of communication traffic increases significantly, the dedicated frequency band and the shared frequency band alone cannot handle the problem, resulting in a decrease in throughput and rejection of communication requests. There was a problem.</p><p> Therefore, the present invention has been made to solve the above problems, and even if the number of users increases and the amount of communication traffic increases accordingly, the throughput decreases and the communication request is rejected. It is an object of the present invention to provide a base station apparatus, a wireless communication system, and a frequency allocation method capable of efficiently using frequency resources without any problems.</p>
<p> In order to achieve the above object, the base station apparatus of the present invention uses at least one first frequency band preferentially assigned to the own apparatus in the base station apparatus capable of communicating with a plurality of mobile stations. At least one second move using at least one first radio communication circuit that communicates with one mobile station and at least one of a plurality of second frequency bands preferentially assigned to other than its own device. The power of the plurality of second radio communication circuits that communicate with the station and the power of the plurality of second frequency bands in the plurality of second radio communication circuits is periodically detected, and the power of the plurality of second frequency bands is detected. A frequency detecting means for detecting the presence / absence of use, a frequency detection result storage means for storing the presence / absence of use of the plurality of second frequency bands detected by the frequency detecting means as a history, the first mobile station, and at least one. In the past, referring to the communication state storage means in which the average communication frequency of information data per unit time during communication of the second mobile station is stored in association with the ID of the mobile station, and the frequency detection result storage means. From the detection result of the presence / absence of use N times, it is determined that there is an unused second frequency band that is not used for communication with the at least one second mobile station, and the first communication state storage means is referred to. When it is determined that the average communication frequency of the first mobile station during communication using one frequency band is equal to or less than a certain value, communication with the first mobile station is not performed from the first frequency band. It is characterized by being provided with a frequency change control means for changing to the second frequency band to be used.</p><p> Further, the base station apparatus of the present invention communicates with at least one first mobile station by using the first frequency band preferentially assigned to the own apparatus in the base station apparatus capable of communicating with a plurality of mobile stations. Communicate with at least one second mobile station using at least one first radio communication circuit and at least one of a plurality of second frequency bands preferentially allocated other than the own device. The frequency for periodically detecting the power of the second radio communication circuit and the plurality of second frequency bands in the plurality of second radio communication circuits to detect the presence / absence of use of the plurality of second frequency bands. The detection means, the frequency detection result storage means for storing the use / non-use of the plurality of second frequency bands detected by the frequency detection means as a history, the first mobile station, and at least one second mobile station. Communication state storage means in which the average communication frequency of information data per unit time during communication and the average data length per unit number of times of the information data are stored in association with the ID of the mobile station, and the frequency detection result storage. Based on the detection result of the presence / absence of use N times in the past with reference to the means, it is determined that there is an unused second frequency band that is not used for communication with the at least one second mobile station, and the communication state storage means is used. When it is determined that the average communication frequency of the first mobile station during communication using the first frequency band is equal to or higher than a certain value and the average data length is equal to or lower than a certain value, the above-mentioned It is characterized by including a frequency change control means for changing communication with the first mobile station from the first frequency band to the unused second frequency band.</p><p> Further, the base station apparatus of the present invention communicates with at least one first mobile station by using the first frequency band preferentially assigned to the own apparatus in the base station apparatus capable of communicating with a plurality of mobile stations. Communicate with at least one second mobile station using at least one first wireless communication circuit and at least one of a plurality of second frequency bands preferentially allocated other than the own device. A frequency that periodically detects the power of the second radio communication circuit and the plurality of second frequency bands in the plurality of second radio communication circuits to detect the presence / absence of use of the plurality of second frequency bands. Communication between the detection means, the frequency detection result storage means that stores the use / non-use of the second frequency band detected by the frequency detection means as a history, and the first mobile station and at least one second mobile station. The communication state storage means in which the average communication frequency of the information data per unit time and the average data length per unit number of the information data are stored in association with the ID of the mobile station, and the frequency detection result storage means. Refer to the communication state storage means for determining that there are a plurality of unused second frequency bands that have not been used for notification with at least one second mobile station based on the detection result of the presence / absence of use N times in the past. When it is determined that the average communication frequency of the first mobile station during communication using the first frequency band is equal to or higher than a certain value and the average data length is equal to or higher than a certain value, the first It is characterized by comprising a frequency change control means for changing communication with one mobile station from the first frequency band to the unused second frequency band having the widest bandwidth from the plurality of unused second frequency bands. And.</p><p> Further, the wireless communication system of the present invention is a base station apparatus that communicates with at least one first mobile station and at least one second mobile station, and the first mobile station and a plurality of second mobile stations. The first mobile station and at least one second mobile station communicate with the base station apparatus using the first frequency band preferentially assigned to the base station apparatus. The second mobile station side radio that communicates with the base station device using at least one of the mobile station side wireless communication circuit and the plurality of second frequency bands preferentially allocated in addition to the base station device. The base station apparatus includes a communication circuit, and the base station apparatus uses the first frequency band to communicate with the first mobile station side wireless communication circuit of the first mobile station. And a plurality of second base station side radios that use at least one of the plurality of second frequency bands to communicate with the second mobile station side radio communication circuit of the at least one second mobile station. Frequency detecting means for periodically detecting the power of the plurality of second frequency bands in the communication circuit and the plurality of second base station side wireless communication circuits to detect the presence or absence of use of the plurality of second frequency bands. A unit of the frequency detection result storage means for storing the use / non-use of the plurality of second frequency bands detected by the frequency detection means as a history, the first mobile station, and at least one second mobile station. The average communication frequency of information data per hour is stored in association with the ID of the mobile station. It is determined that there is an unused second frequency band that is not used for communication with the two second mobile stations, and the first frequency band is being communicated using the first frequency band with reference to the communication state storage means. When it is determined that the average communication frequency of the mobile station 1 is equal to or less than a certain value, the frequency change control means for changing the communication with the first mobile station from the first frequency band to the unused second frequency band. It is characterized by having and.</p><p> Further, the wireless communication system of the present invention is a base station apparatus that communicates with at least one first mobile station and at least one second mobile station, and the first mobile station and a plurality of second mobile stations. The first mobile station and at least one second mobile station communicate with the base station apparatus using the first frequency band preferentially assigned to the base station apparatus. The second mobile station side radio that communicates with the base station device using at least one of the mobile station side wireless communication circuit and the plurality of second frequency bands preferentially allocated in addition to the base station device. The base station apparatus includes a communication circuit, and the base station apparatus uses the first frequency band to communicate with the first mobile station side wireless communication circuit of the first mobile station. And a plurality of second base station side radios that use at least one of the plurality of second frequency bands to communicate with the second mobile station side radio communication circuit of the at least one second mobile station. Frequency detecting means for periodically detecting the power of the plurality of second frequency bands in the communication circuit and the plurality of second base station side wireless communication circuits to detect the presence or absence of use of the plurality of second frequency bands. The frequency detection result storage means for storing the use / non-use of the plurality of second frequency bands detected by the frequency detection means as a history, the first mobile station, and the at least one second mobile station. Refer to the communication state storage means in which the average communication frequency of information data per unit time and the average data length per unit number of times of the information data are stored in association with the ID of the mobile station, and the frequency detection storage means. From the detection result of the presence / absence of use N times in the past, it is determined that there is an unused second frequency band that is not used for communication with the at least one second mobile station, and the first communication state storage means is referred to. When it is determined that the average communication frequency of the first mobile station during communication using one frequency band is equal to or higher than a certain value and the average data length is equal to or lower than a certain value, the first mobile station It is characterized by comprising a frequency changing means for changing communication with and from the first frequency band to the unused second frequency band.To.</p><p> Further, the frequency allocation method of the present invention may be performed during communication between the base station apparatus and at least one first mobile station using the first frequency band preferentially allocated to the base station apparatus. Detecting an unused second frequency band from a plurality of second frequency bands preferentially assigned in addition to the base station device used for communication between the base station device and at least one second mobile station. It is a method of allocating, periodically detecting the power of the plurality of second frequency bands, detecting the use / non-use of the plurality of second frequency bands, and history of the detected use / non-use of the plurality of second frequency bands. The average communication frequency of information data per unit time of the first mobile station and at least one second mobile station is calculated, and the frequency detection result storage means is referred to. The unused second frequency band that has not been used for communication with the at least one second mobile station is detected from the detection result of the presence / absence of use N times in the past, and communication is performed using the first frequency band. When the average communication frequency of the first mobile station is equal to or less than a certain value, communication with the first mobile station is assigned from the first frequency band to the unused second frequency band. To do.</p><p> Further, the frequency allocation method of the present invention may be performed during communication between the base station apparatus and at least one first mobile station using the first frequency band preferentially allocated to the base station apparatus. Detecting an unused second frequency band from a plurality of second frequency bands preferentially assigned in addition to the base station device used for communication between the base station device and at least one second mobile station. It is a method of allocating, periodically detecting the power of the plurality of second frequency bands, detecting the use / non-use of the plurality of second frequency bands, and history of the detected use / non-use of the plurality of second frequency bands. The average communication frequency of information data per unit time of the first mobile station and at least one second mobile station and the average data length per unit number of times of the information data are stored in the frequency detection result storage means. The unused second frequency band that has not been used for communication with the at least one second mobile station is detected from the detection result of the past N times of use or non-use by referring to the frequency detection result storage means. When the average communication frequency of the first mobile station during communication using the first frequency band is equal to or higher than a certain value and the average data length is equal to or lower than a certain value, the first mobile station It is characterized in that communication with is allocated from the first frequency band to the unused second frequency band.</p>
<p> According to the present invention, even if the number of users increases and the amount of communication traffic increases accordingly, it is possible to efficiently use frequency resources without causing a decrease in throughput or rejection of communication requests. Radio communication systems, base station devices and frequency allocation methods can be provided.</p>
Hereinafter, examples of the present invention will be described with reference to the drawings.
The first embodiment of the present invention will be described with reference to FIGS. 1 to 14. First, the configuration of the wireless communication system according to this embodiment will be described with reference to FIG. In the wireless communication system shown in FIG. 1, the base station apparatus 100 has a plurality of mobile stations 201, 202, ... (In FIG. 1, the number of mobile stations is 4) and, for example, time division multiplexing access. Wireless communication is performed by a communication method such as a method or a frequency division multiplexing access method.
Here, the frequency band assigned in advance to this wireless communication system (hereinafter, referred to as the first wireless communication system) is used for the wireless communication between the base station apparatus 100 and the mobile stations 201 and 202. Further, for wireless communication between the base station apparatus 100 and the mobile stations 203,204, some of the plurality of frequency bands assigned to other wireless communication systems (hereinafter referred to as the second wireless communication system), which will be described later, will be used. A frequency band that satisfies the above conditions is used. That is, the base station apparatus 100 wirelessly communicates with a plurality of mobile stations 201, 202, ... Using a plurality of frequency bands.
Here, the details of the frequency band used for the above-mentioned wireless communication will be described with reference to FIG. The frequency band FC in FIG. 2 is a frequency band pre-allocated to the first wireless communication system. Further, the frequency bands F1, F2, ..., Fm are not always used in the second wireless communication system among the frequency bands assigned to the second wireless communication system, and the communication of the first wireless communication system. It is a frequency band that satisfies the conditions such as not being used in or near the area range and not being used for highly urgent applications. The frequency bands F1, F2, ..., Fm are predetermined by the first wireless communication system.
The base station apparatus 100 stores these frequency bands FC, F1, F2, ..., Fm as frequency bands that can be used for wireless communication in advance, and depending on the situation, mobile stations 201, 202, ... Used for wireless communication. In this embodiment, the frequency bands FC, F1, F2, ..., Fm are all set to X [MHz] having the same frequency bandwidth.
Next, configuration examples of the base station apparatus 100 and mobile stations 201, 202, ... Consisting of the wireless communication system according to the present embodiment will be described with reference to FIGS. 3 and 8. FIG. 3 shows a configuration example of the base station apparatus 100. The base station device 100 shown in FIG. 3 has a first wireless communication circuit 11 corresponding to the frequency band FC, a second wireless communication circuit 12-1, ... ·, 12-N (N> m), transmission control circuit 13, reception control circuit 14, control unit 15 are provided.
Subsequently, the detailed configuration of each part will be described. The first wireless communication circuit 11 includes a transmitting antenna 111, a receiving antenna 112, a transmitting wireless processing circuit 113 connected to the transmitting antenna 111, a receiving wireless processing circuit 114 connected to the receiving antenna 112, and the above. It has a modulation circuit 115 connected between the transmission control circuit 13 and the transmission radio processing circuit 113, and a demodulation circuit 116 connected between the reception radio processing circuit 114 and the reception control circuit 14, and has a frequency band. Send and receive data using FC. Further, the second wireless communication circuit 12-1 has a frequency detection circuit 127-1 connected to the control unit 15 in addition to the components of the first wireless communication circuit 11, and the control unit 15 Data is transmitted and received using one of the frequency bands F1, F2, ..., Fm according to the instructions from. Since the second wireless communication circuits 12-2, ..., 12-N have the same configuration as the second wireless communication circuit 12-1, the description thereof will be omitted.
Next, the control unit 15 has a frequency allocation storage unit 151, a frequency detection result storage unit 152, and a communication state storage unit 153. Then, the control unit switches transmission / reception of the first wireless communication circuit 11 and the second wireless communication circuits 12-1, ..., 12-N and generates control data, and also performs frequency bands FC, F1, The frequency band used for communication between the base station device 100 and the mobile stations 201, 202, ... Is determined according to the usage status of F2, ..., Fm and the like.
Subsequently, the frequency allocation storage unit 151, the frequency detection result storage unit 152, and the communication state storage unit 153 will be described with reference to FIGS. 4 to 6. First, FIG. 4 is a diagram showing an example of a table of the frequency allocation storage unit 151. In this table, IDs for identifying mobile stations 201, 202, ... With which the base station device 100 is communicating and communication with mobile stations 201, 202, ... Corresponding to each mobile station ID are used. The used frequency band 154 is stored. In the example shown in FIG. 4, there are five mobile stations communicating with the base station device 100, of which the mobile station with the mobile station ID 3 is communicating using the frequency band F2, and the rest. The four mobile stations (IDs "1", "2", "4", "5") communicate using the frequency band FC.
Next, FIG. 5 is a diagram showing an example of a table of the frequency detection storage unit 152. In this table, for each frequency band F1, F2, ..., Fm, the frequency detection results 1 to n of the past n times (n is an arbitrary integer, n = 5 in Fig. 5), this frequency detection The frequency usable flag 156 and the frequency used state flag 157 calculated based on the results 1 to n are stored.
In the table shown in FIG. 5, the results of the past five frequency detections performed for each frequency band F1, F2, ..., Fm are stored in each frequency detection result 1 to 5. The newest detection result is stored in frequency detection result 1, and the oldest detection result is stored in frequency detection result 5. The frequency band in which the frequency detection result 1 is "1" (for example, F1) is the frequency band in which the second wireless communication system uses the frequency band for communication and the frequency detection result 1 is "0" (for example). For example, F3, Fm) indicates that the second radio communication system does not use that frequency for communication. Further, it is shown that the frequency band (for example, F2) in which the frequency detection result 1 is "N / A" is already used for communication with the mobile stations 201, 202, ....
In addition, the frequency usable flag 156 is set so that the base station device 100 communicates with the mobile stations 201, 202, ... Using the frequency bands F1, F2, ..., Fm based on the frequency detection results 1 to 5 of the past five times. The result of calculating whether or not it is possible is stored. The frequency band in which the frequency usable flag 156 is "1" (for example, F3) can be used for communication with mobile stations 201, 202, ..., And the frequency band in which "0" is "0" (for example, F1) is , Mobile stations 201, 202, ... Indicates that it cannot be used for communication. Similar to the frequency detection results 1 to 5, this frequency usable flag 156 also has "N /" in the frequency band (for example, F2) already used for communication between the base station device 100 and the mobile stations 201, 202, ... "A" is written.
Further, the frequency usage status flag 157 stores whether or not each frequency band F1, F2, ..., Fm is used for communication between the base station device 100 and the mobile station 201, 202, .... .. The frequency band in which the frequency usable flag 157 is "1" (for example, F2) is the frequency band in which the base station device 100 is used for communication with the mobile stations 201, 202, ..., And is "0". (For example, F1, F3, Fm) means that it is not used for communication with mobile stations 201, 202, ....
Next, FIG. 6 is a diagram showing an example of a table of the communication state storage unit 153. This table stores the average communication frequency 158 and the average information data length 159 for the ID unique to each mobile station as the communication state between the base station apparatus 100 and each mobile station 201, 202, .... Here, the average communication frequency 158 is the number of times information data is transmitted to mobile stations 201, 202, ... Per predetermined unit time, and the average information data length 159 is the number of times information data such as application data is transmitted. It is the average data length per unit.
Next, the configurations of mobile stations 201, 202, ... Will be described with reference to FIGS. 7 and 8. Since a plurality of mobile stations 201, 202, ... That communicate with the base station apparatus 100 have the same configuration, the configuration of the mobile stations 201, 202 will be described here as a representative example 200.
The mobile station 200 shown in FIG. 7 includes a first wireless communication circuit 21, a second wireless communication circuit 22, a transmission control circuit 23, a reception control circuit 24, and a control unit 25. The first wireless communication circuit 21 has the same configuration as the first wireless communication circuit 11 of the base station apparatus 100 shown in FIG. Further, the second wireless communication circuit 22 has almost the same configuration as the second wireless communication circuit 12 of the base station apparatus 100 shown in FIG. 3, but the second wireless communication circuit 12 of the base station apparatus 100 has. It does not have the frequency detection circuit 127. Further, the control unit 25 has a frequency allocation storage unit 251.
FIG. 8 shows an example of the table of the frequency allocation storage unit 251 and stores the frequency band used for communication with the base station apparatus 100. In the example of FIG. 8, since the mobile station 200 communicates using the frequency band FC, the frequency allocation storage unit 251 of FIG. 8 stores "FC" as the used frequency band 154.
Subsequently, the operations of the base station apparatus 100 and the mobile stations 201, 202, ... Will be described with reference to FIGS. 3 to 14. First, the operation when the base station apparatus 100 transmits / receives data will be described with reference to FIG. When transmitting information data such as application data, this information data is input to the transmission control circuit 13 from the upper layer. Similarly, when the control data generated by the control unit 15 is transmitted, the control data is input from the control unit 15 to the transmission control circuit 13. Hereinafter, this information data and control data are collectively referred to as transmission data.
The transmission control circuit 13 outputs the input transmission data to any one of the first wireless communication circuit 11 or the second wireless communication circuits 12-1, ..., 12-N. The wireless communication circuit 12-k (k is one of 1,2,3..N) that outputs this transmission data is determined by the notification from the control unit 15. Since the operation of the wireless communication circuit to which the transmission data is input is the same for both the first wireless communication circuit 11 and the second wireless communication circuit 12-k, here, the transmission data is the first wireless communication circuit. The case where it is input to 11 will be described.
The transmission data input to the first wireless communication circuit 11 is first subjected to processing such as error correction coding by the modulation circuit 115, modulated by a predetermined modulation method, and output to the transmission wireless processing circuit 113. Will be done. Next, the transmission wireless processing circuit 113 performs wireless processing such as D / A conversion, quadrature modulation, up-conversion, band limitation, and power amplification on the input transmitted data after modulation to generate a wireless signal. To do. The generated radio signal is transmitted to the mobile station via the transmitting antenna 111. The frequency band of the radio signal processed and transmitted by the second wireless communication circuit 12-k is determined by the notification from the control unit 15.
Next, a case where the base station apparatus 100 receives data will be described. The radio signals received by the receiving antenna 112 or the receiving antennas 122-1, ..., 122-N are input to the receiving radio processing circuits 114, 124-1, ..., 124-N, respectively. Since the radio signals input to the reception radio processing circuits 114, 124-1, ..., 124-N are subjected to the same processing thereafter, the processing of the radio signals input to the reception radio processing circuit 114 is performed here. Will be described.
The reception radio processing circuit 114 performs radio processing such as power amplification, band limitation, down-conversion, orthogonal demodulation, and A / D conversion on the input radio signal, generates received data, and outputs it to the demodulation circuit 116. To do. Next, the demodulation circuit 116 demodulates the input received data, performs processing such as error correction and decoding, and outputs the data to the reception control circuit 14. Next, the reception control circuit 14 outputs the information data to the upper layer based on the determination of the header unit of the received received data, and outputs the control data to the control unit 15.
By the way, when communicating with mobile stations 201, 202, ..., Or performing frequency detection process A, the control unit 15 selects the second wireless communication circuit 12-k, and the second wireless communication circuit 12-k is selected. Notify the communication circuit 12-k of the frequency band of the received radio signal. Therefore, the reception radio processing circuit 124-k of the selected second radio communication circuit 12-k performs radio processing according to the notified frequency band. Further, the reception radio processing circuit 124-k outputs the received data to the demodulation circuit 126-k or the frequency detection circuit 127-k in accordance with the notification from the control unit 15. Next, the demodulation circuit 126-k demodulates the input received data, performs processing such as error correction and decoding, and outputs the data to the reception control circuit 14. On the other hand, the frequency detection circuit 127-k measures the power of the input received data as a part of the frequency detection process A described later, and outputs the result to the control unit 15.
Next, since the mobile stations 201, 202, ... Send and receive data in the same manner as the base station apparatus 100 shown in FIG. 3, the description thereof will be omitted. However, since mobile stations 201, 202, ... Have only one second wireless communication circuit 22, when transmitting and receiving data using the frequency bands F1, F2, ..., Fm, This second wireless communication circuit 22 is used. The frequency band of the wireless signal transmitted / received from the second wireless communication circuit 22 is determined by the notification from the control unit 25.
(Wireless communication between base station device 100 and mobile station 201) Subsequently, the wireless communication performed between the base station apparatus 100 and the mobile stations 201, 202, ... Will be described with reference to FIG. FIG. 9 is a diagram showing a sequence of wireless communication between the base station apparatus 100 and the mobile stations 201 and 202. Note that FIG. 9 shows an example in which the mobile station 201 requests the base station device 100 to start wireless communication to start wireless communication, but the base station device 100 requests the mobile station 201 to start wireless communication. May request the start of wireless communication.
First, the base station apparatus 100 sets a frequency band used for communication with the mobile station 201 in advance before starting communication with the mobile station 201 (501). The set frequency band includes the frequency bands F1, ..., Fm assigned to the second wireless communication system in addition to the frequency band FC assigned to the first wireless communication system. In addition, setting means identifying the frequency band excluding the frequency band that is always used by the second wireless communication system and the frequency band that is used for urgent applications, and determining the center frequency thereof. To do.
However, in order to use these frequency bands for communication with the mobile station 201, it is a condition that they are not used by the second wireless communication system. Therefore, the control unit 15 periodically executes the frequency detection process A for the set frequency band regardless of whether or not it is communicating with the mobile station 201, and every frequency band F1, ..., Fm. The frequency detection result storage unit 152 is updated by determining whether or not it is used (502).
Next, when starting wireless communication between the mobile station 201 and the base station apparatus 100, the mobile station 201 requests the base station apparatus 100 to start wireless communication using the frequency band FC (503). Similarly, the base station apparatus 100 that has received the request notifies the mobile station 201 of the wireless communication start response using the frequency band FC (504). As a result, the mobile station 201 and the base station device 100 are electrically connected, and wireless communication is started. At this time, the frequency band used for communication is FC, and this frequency band FC is stored in the frequency allocation storage unit 151 of the base station device 100 and the frequency allocation storage unit 251 of the mobile station 201, and the frequency band FC is also stored in the subsequent communication. This frequency band FC is used (505).
Next, the base station apparatus 100 periodically performs frequency change evaluation B1 while communicating with the mobile station 201, and evaluates the optimum frequency band for communication with the mobile station 201 (506 of R1). The details of this frequency change evaluation B1 will be described later. As a result of performing this frequency change evaluation B1, if it is evaluated that the frequency band currently used for communication (frequency band FC in FIG. 9) should be maintained, the base station apparatus 100 continues to use the frequency band FC. Communicates with mobile station 201 (507 of R1).
On the other hand, if it is evaluated that the frequency band FC currently used for communication should be changed to the optimum frequency band (for example, F3) by performing the frequency change evaluation B1 (506 of R2), the base station apparatus 100 The control unit 15 decides to communicate with the mobile station 201 using the frequency band F3, and notifies the mobile station 201 of the change to the frequency band F3 using the frequency band FC before the change (the change to the frequency band F3). R2 508). Further, the control unit 15 updates the used frequency band 154 stored in the frequency allocation storage unit 151 to F3, and updates F3 of the frequency detection connection 1 of the frequency detection result storage unit 152 to N / A. .. On the other hand, the control unit 25 of the mobile station 201 that received the notification changes the frequency band 154 used by the frequency allocation storage unit 251 to "F3" accordingly, and uses the frequency band F3 to send a frequency change notification response to the base station. Notify device 100 (509 of R2). From this point onward, the base station apparatus 100 and the mobile station 201 communicate using the frequency band F3 (510 of R2).
(Frequency detection process A) Subsequently, the frequency detection process A performed by the control unit 15 of the base station apparatus 100 will be described with reference to the flowchart of FIG. The control unit 15 refers to the frequency detection result storage unit 152 every time a certain cycle elapses, and among the stored frequency bands F1, ..., Fm, the frequency band in which the frequency detection process A is not performed. Select one (step S101). Here, it is assumed that the frequency band F1 is selected. Next, the control unit 15 refers to the frequency usage status flag 157 of the selected frequency band F1, and whether or not the frequency usage status flag 157 of this frequency band F1 is "0" (that is, whether the frequency band F1 can be used). Whether or not) is determined (step S102).
As a result of this determination, if the frequency usage status flag 157 is "1" (unusable) and the processing of all frequency bands is not completed (No in steps S102 and S110), the determination of the next frequency band is made. Return to step S101. On the other hand, as a result of this determination, when the frequency usage status flag 157 is "0" (available) (Yes in step S102), the control unit 15 is executing the frequency detection process A, the mobile stations 201, 202, ... -Select a wireless communication circuit that is not used for communication with the second wireless communication circuit 12-1, ..., 12-N, and instruct the selected second wireless communication circuit to detect the frequency. give. Here, it is assumed that, for example, the second wireless communication circuit 12-1 is selected.
The reception radio processing circuit 124-1 of the selected second radio communication circuit 12-1 receives the radio signal of the frequency band F1 via the antenna 122-1 to confirm that it is unused. Further, the frequency detection circuit 127-1 measures the power of the received signal, and outputs the result to the control unit 15 (step S103). Next, the control unit 15 compares the power measurement result input from the frequency detection circuit 127-1 with the predetermined threshold value Th1 (step S104). As a result of comparison, if the power measurement result is equal to or higher than the threshold value Th1 (Yes in step S104), the control unit 15 determines that the second wireless communication system uses the frequency band F1, and the frequency detection result storage unit 152. The detection result "1" is stored in the frequency detection result 1 (see FIG. 5) of (step S105). On the other hand, if the power measurement result is smaller than the threshold value Th1 (No in step S104), the control unit 15 determines that the second wireless communication system does not use the frequency band F1, and the detection result " 0 is stored (step S106). At the same time, the control unit 15 also updates the frequency detection results 2 to N.
Next, the control unit 15 refers to the updated frequency detection results 1 to N, and determines whether or not all of these frequency detection results 1 to N are 0 (step S107). If the frequency detection results 1 to N are all "0", it is determined that the frequency band F1 can be used for communication with mobile stations 201, 202, ..., And the frequency usable flag 156 of the frequency band F1 is set to "1". Remember (step S108). On the other hand, if even one of the frequency detection results 1 to N stores "1", it is determined that the frequency band F1 cannot be used for communication with mobile stations 201, 202, ..., And the frequency usable flag 156 Store "0" in (step S109).
The above is the frequency detection process for one frequency band, and it is determined whether or not this process has been performed for all frequency bands F1, ..., Fm (step S110), and all frequency bands F1, ... If performed for Fm, the frequency detection process is terminated. If there is a frequency band for which frequency detection processing has not been executed, the process returns to step S101 and steps S101 to S110 are executed.
(Frequency change evaluation process B1) Subsequently, the frequency change evaluation process B1 performed by the control unit 15 of the base station apparatus 100 will be described with reference to the flowcharts of FIGS. 11 to 14. FIG. 11 shows a flowchart of the frequency change evaluation process B1. The frequency change evaluation process B1 is executed with a lapse of a certain cycle while the base station apparatus 100 is communicating with any of the mobile stations 201, 202, ....
First, when a certain cycle elapses, the control unit 15 selects one of the mobile stations 201, 202, ... That are performing wireless communication, refers to the communication state storage unit 153 (step S111), and selects the one. The evaluation process C1 described later is executed for the mobile station (step S112). In the following description, it is assumed that the mobile station 201 is selected.
If it is determined as a result of the evaluation process C1 in step S112 that the frequency band used for communication with the mobile station 201 is changed (Yes in step S113), the control unit 15 is stored in the frequency allocation storage unit 151. The frequency band 154 used by the mobile station 201 is updated (step S114). Further, the control unit 15 updates the frequency usage status flag 157 of the frequency band Fi (i is 1,2,3..m) to be changed stored in the frequency detection result storage unit 152 to 1 (step). S115).
The above is the frequency change evaluation process for the mobile station 201, and it is determined whether or not this process has been performed for all the mobile stations 201, 202, ... Communicating with the base station apparatus 100 (step S116). Then, when this processing is performed for all mobile stations 201, 202, ..., The frequency change evaluation processing B1 is terminated. On the other hand, if there is a mobile station that has not yet executed the frequency change evaluation process, the process returns to step S111 and steps S111 to S116 are executed.
(Evaluation process C1) Subsequently, the evaluation process C1 described above will be described with reference to FIGS. 12 to 14. Here, a case where the evaluation process is performed on the mobile station 201 following the frequency change evaluation process will be described.
In the case of the evaluation process C1 shown in FIG. 12, the control unit 15 first refers to the frequency allocation storage unit 151, and the frequency band used for the mobile station 201 is the frequency assigned to the first wireless communication system. It is determined whether or not the band FC is used (step S121). If the frequency band used 154 is not "FC", it is determined that the frequency band is not changed and the process is terminated.
On the other hand, when the frequency band 154 used is "FC", the value of the average communication frequency 158 (see FIG. 6) stored in the ID of the mobile station 201 is determined in advance by referring to the communication state storage unit 153. It is determined whether or not the threshold value is Th2 or higher (step S122). When the value of the average communication frequency 158 is smaller than the threshold value Th2, it is determined that the frequency band is not changed and the process is terminated.
On the other hand, when the average communication frequency 158 is the threshold value Th2 or more, the communication state storage unit 153 is referred to again, and the value of the average information data length 159 (see FIG. 6) stored in the ID of the mobile station 201 is determined in advance. It is determined whether or not the threshold value is Th3 or less (step S123). As a result of the determination, when the value of the average information data length 159 is larger than the threshold value Th3, it is determined that the frequency band is not changed and the process is terminated.
On the other hand, when the average information data length 159 is the threshold value Th3 or less, it is determined whether or not there is a changeable frequency band by referring to the frequency usable flag 156 of the frequency detection result storage unit 152. That is, if the frequency usable flags 156 of all frequency bands F1, ..., Fm are referred to and all the frequency usable flags 156 are "0", there is no changeable frequency band and the frequency is used. If there is at least one frequency band for which the enable flag 156 is "1", it is determined that there is a changeable frequency band (step S124).
As a result of this determination, if there is no changeable frequency band, it is determined that the frequency band is not changed and the process is terminated. On the other hand, when it is determined that the frequency band Fi that can be changed exists, the control unit 15 determines to change the frequency band Fi (step S125).
At this time, as shown in FIG. 5, when the frequency band Fi in which the frequency enable flag 156 is 1 is only F3, the control unit 15 determines to use the frequency band F3. When a plurality of frequency usable flags 156 are set to "1", for example, the frequency band Fi closest to the frequency band FC assigned to the first wireless communication system is selected, and the control unit 15 moves. Decide to use this frequency band Fi for communication with station 201.
That is, in this evaluation process C1, the communication state of the mobile stations 201, 202, ... Is evaluated, and when there is a mobile station that frequently communicates a small amount of information data, the frequency band F1, ..., Fm Change the frequency band to communicate using either.
(Evaluation process C2) Next, a modified example of the evaluation process C1 will be described with reference to FIG. In the evaluation process C1 shown in FIG. 12, it is determined in step S122 whether or not the value of the average communication frequency 158 is equal to or higher than the threshold value Th2, but in the evaluation process C2 shown in FIG. 13, the average communication frequency 158 is instead. The difference is that it is determined whether or not the value of is equal to or less than the threshold value Th4 (step S126). That is, in this evaluation process C2, the communication state of the mobile stations 201, 202, ... Is evaluated, and when there is a mobile station that communicates a small amount of information data at a low frequency, the frequency band F1, ..., Fm The frequency band is changed so that communication is performed using either of them.
(Evaluation process C3) Subsequently, another modification of the evaluation process C2 will be described with reference to FIG. The evaluation process C3 shown in FIG. 14 performs almost the same process as the evaluation process C2 shown in FIG. 13, but compares the value of the average information data length 159 performed in step S123 of the evaluation process C2 with the threshold value Th3. The difference is that it is not. That is, in this evaluation process C3, the communication state of the mobile stations 201, 202, ... Is evaluated, and when there is a mobile station having a low average communication frequency 158, one of the frequency bands F1, ..., Fm is used. The frequency band is changed so that communication is performed using.
As described above, according to the first embodiment, the plurality of frequency bands F1, ..., Fm assigned to the second wireless communication system are set to the base station apparatus 100 and the mobile stations 201, 202, ... By using it for communication between, it corresponds to the increase in the number of users of the first wireless communication system and the accompanying increase in the amount of communication traffic, and as long as there is no decrease in throughput or rejection of communication requests. A certain frequency resource can be used efficiently. Further, the frequency band FC used for communication between the base station device 100 and the mobile stations 201, 202, ... Is not used for a certain period of time by the second wireless communication system, and the frequency band F1, ... By limiting mobile stations 201,202, ..., Which are selected from, Fm and communicate in the selected frequency band, to mobile stations that satisfy predetermined conditions, such as communicating a small amount of information data with high frequency. , The interference given to the second wireless communication system can be reduced.
Next, a second embodiment of the present invention will be described with reference to FIGS. 15 to 19. The configurations of the first and second wireless communication systems, the base station apparatus 100, and the mobile stations 201, 202, ... According to the second embodiment are the first and second wireless communication systems and bases shown in FIGS. 1 to 7. Since the configurations are the same as those of the station device 100 and the mobile stations 201, 202, ..., the same reference numerals are given and the description thereof will be omitted.
Subsequently, the operation of the base station apparatus 100 according to the second embodiment will be described with reference to FIGS. 15 to 19. In this embodiment, in the frequency change evaluation process B2 performed by the control unit 15 of the base station apparatus 100, the frequency change is determined in consideration of the utilization efficiency E of the frequency band FC assigned to the first wireless communication system in advance. However, since the operations of the other base station devices 100 and the operations of the mobile stations 201, 202, ... Are the same as those in the first embodiment, the description thereof will be omitted.
(Frequency change evaluation process B2) The frequency change evaluation process B2 according to this embodiment will be described with reference to the flowchart of FIG. When a certain cycle elapses while the base station apparatus 100 and the mobile stations 201, 202, ... Are communicating, the control unit 15 of the base station apparatus 100 starts the frequency change evaluation process B2. First, the control unit 15 refers to the communication state storage unit 153 and performs the utilization efficiency evaluation process D1 for the frequency band FC (step S201). This utilization efficiency evaluation process D1 will be described later.
As a result of this utilization efficiency evaluation process D1, when it is determined that the frequency bands F1, F2, ..., Fm assigned to the second wireless communication system should be used (No in step S202), the frequency change process is Since it is the same as the frequency change evaluation process B1 shown in FIG. 11, the same reference numerals (steps S111 to S116) are added and the description thereof will be omitted.
If, as a result of the utilization efficiency evaluation process D1, it is determined that the frequency band FC should be used instead of the frequency bands F1, F2, ..., Fm (Yes in step S202), the control unit 15 assigns the frequency. With reference to the storage unit 151 (step S202), it is checked whether or not there are mobile stations 201, 202, ... Communicating using the frequency bands F1, F2, ..., Fm (step S203). As a result, if the mobile stations 201, 202, ... Communicating using the frequency bands F1, F2, ..., Fm do not exist, the frequency change evaluation process B2 is terminated.
On the other hand, if there is a mobile station 201,202, ... Communicating using the frequency bands F1, F2, ..., Fm (Yes in step S204), communication to this mobile station 201,202, ... Change the frequency band to be used to "FC" (step S205). Next, the frequency used frequency 154 of the frequency allocation storage unit 151 is updated (step S206), and then the frequency usage status flag 157 of the frequency detection result storage unit 152 is updated (step S207).
(Usage efficiency evaluation process D1) Subsequently, the utilization efficiency evaluation process D1 for the frequency band FC will be described with reference to FIGS. 16 to 19. FIG. 16 shows a flowchart of the utilization efficiency evaluation process D1 performed by the control unit 15.
First, the control unit 15 refers to the communication state storage unit 153 and finds out a mobile station using the frequency band FC for communication. Next, the control unit 15 calculates the utilization efficiency E of the frequency band FC in the found mobile station (step S211). Here, the utilization efficiency E is calculated by multiplying the value of the average communication frequency 158 and the value of the average information data length 159 for each mobile station, and totals all the found mobile stations. Then, the control unit 15 compares the threshold value Th5 determined in advance with the utilization efficiency E (step S212), and if the utilization efficiency E is larger than the threshold value Th5, the frequency bands F1, F2, ..., Fm The use is decided (step S213), and if it is small, the utilization efficiency evaluation process D1 is finished without making a decision.
(Usage efficiency evaluation process D2) Next, the utilization efficiency evaluation process D2, which is a modification of the utilization efficiency evaluation process D1 shown in FIG. 17, will be described. In this utilization efficiency evaluation process D2, instead of calculating the utilization efficiency E, the number of mobile stations using the frequency band FC for communication is counted (step S214), and the number of mobile stations is determined in advance. The point at which the set threshold value Th6 is compared (step S215) is different from the utilization efficiency evaluation process D1 shown in FIG.
(Usage efficiency evaluation process D3) Subsequently, another modification of the utilization efficiency evaluation process D1 will be described with reference to FIGS. 18 and 19. In the utilization efficiency evaluation process D3, which is a modification of the utilization efficiency evaluation process D1, instead of calculating the utilization efficiency E, the total communication wait frequency F of each mobile station is calculated (step S216), and the communication wait frequency F of this communication wait frequency F is calculated. The point at which the total is compared with the predetermined threshold value Th7 (step S217) is different from the utilization efficiency evaluation process D1 shown in FIG. Here, the communication waiting frequency F is how long the transmission data cannot be transmitted due to reasons such as the frequency resources being used by other mobile stations, although the transmission data for the mobile station exists. , It is assumed that the data is counted at regular intervals. When the control unit 15 performs the utilization efficiency evaluation process D3, as shown in FIG. 19, the communication state storage unit 153 has a configuration capable of newly storing the communication waiting frequency F in addition to the configuration of FIG.
As described above, according to the second embodiment, the same effect as that of the first embodiment can be obtained, and the frequency band is based on the utilization efficiency evaluation process D1 of the frequency band FC assigned to the first wireless communication system. By deciding whether or not to communicate using FC, excessive interference is given to the second wireless communication system when the frequency band allocated to the second wireless communication system is used more than necessary. The problem of getting rid of it can be solved.
Next, a third embodiment will be described with reference to FIGS. 20 to 24. As shown in FIG. 20, in the third embodiment, the bandwidths of the frequency bands F1, F2, ..., Fm assigned to the second wireless communication system are different. Therefore, as shown in FIG. 21, the frequency detection result storage unit 160 of the base station apparatus 100 has a configuration of further storing the frequency bandwidth 161 in addition to the configuration of the frequency detection result storage unit 152 shown in FIG. .. Since the configurations of the base station apparatus 100 other than the frequency detection result storage unit 160 and the configurations of the mobile stations 201, 202, ... Are the same as the configurations of the first embodiment, the same reference numerals are given and the description thereof will be omitted. ..
Subsequently, the operations of the base station apparatus 100 and the mobile stations 201, 202, ... In this embodiment will be described with reference to FIGS. 22 to 24. The operation of the base station apparatus 100 and the mobile stations 201, 202, ... In the third embodiment is when communication is performed using the frequency bands F1, F2, ..., Fm assigned to the second wireless communication system. , The content that the control unit 15 of the base station device 100 and the control unit 25 of the mobile stations 201, 202, ... Notify the second wireless communication circuits 12-1, ..., 12-N, 22, and the base station. The evaluation process C4 in the frequency change evaluation process B1 performed by the control unit 15 of the device 100 is different, but the other operations are the same as those in the first embodiment, and thus the description thereof will be omitted.
First, the operations of the control units 15 and 25 will be described with reference to FIGS. 3 and 7.
The control unit 15 of the base station apparatus 100 shown in FIG. 3 is a second wireless communication circuit 12-1, ..., Used for transmission and reception when communicating using the frequency bands F1, ..., Fm. The radio processing circuits 123-1,124-1 ..., 123-N, 124-N of 12-N are notified of the frequency bands F1, ..., Fm used for communication, and this frequency band F1 , ..., also notifies the bandwidth of Fm.
Similarly, the control unit 25 of the mobile stations 201, 202, ... Shown in FIG. 7 also has a frequency band F1, which is used for communication with respect to the radio processing circuits 223, 224 of the second wireless communication circuit 22 used for transmission and reception. ..., Fm is notified, and the bandwidth of this frequency band is also notified.
(Evaluation process C4) Next, the evaluation process C4 in the frequency change evaluation process B1 performed by the control unit 15 of the base station apparatus 100 will be described with reference to FIGS. 22 to 24. When the evaluation process C4 shown in FIG. 22 decides to change the frequency band, the point that the evaluation process C4 decides to change the frequency band when there is a mobile station that frequently communicates a small amount of information data is shown in FIG. Since it is the same as the evaluation process C1, the same reference numerals (steps S121 to S124) are added and the description thereof will be omitted. In this evaluation process C4, when the frequency band change is determined and the changed frequency band is selected, if there are a plurality of changeable frequency bands, the frequency band having the narrowest bandwidth is selected (step S301). ..
(Evaluation process C5) Subsequently, the evaluation process C5 shown in FIG. 23 will be described. This evaluation process C5 evaluates the communication state of the mobile station, and when it is decided to change the frequency band, it decides to change the frequency band when there is a mobile station that communicates a small amount of information data at a low frequency. Is the same as the evaluation process C2 shown in FIG. 13, so the same reference numerals (steps S121, S126, S123, S124) are added and the description thereof will be omitted. In this evaluation process C5, when the frequency band change is determined and the changed frequency band is selected, if there are a plurality of changeable frequency bands, the frequency band having the smallest bandwidth is selected (step S302). ..
(Evaluation process C5) Next, the evaluation process C6 shown in FIG. 24 will be described. Here, a case where the evaluation process C6 is performed on the mobile station 201 will be described. In the case of the evaluation process C6 shown in FIG. 24, the control unit 15 first refers to the frequency allocation storage unit 151, and the frequency band used for the mobile station 201 is the frequency assigned to the first wireless communication system. It is determined whether or not the band FC is used (step S311). If the frequency band used 154 is not "FC", the control unit 15 determines that the frequency band is not changed and ends the process C6.
On the other hand, when the frequency band 154 used is "FC", the control unit 15 refers to the communication state storage unit 153, and the value of the average communication frequency 158 (see FIG. 6) stored in the ID of the mobile station 201 is set in advance. It is determined whether or not the determined threshold value is Th7 or higher (step S312). If the value of the average communication frequency 158 is smaller than the threshold value Th7, it is determined that the frequency band is not changed, and the process C6 is terminated.
On the other hand, when the value of the average communication frequency 158 is the threshold value Th7 or more, the control unit 15 refers to the communication state storage unit 153 again, and the value of the average information data length 159 (see FIG. 6) stored in the ID of the mobile station 201. However, it is determined whether or not it is equal to or higher than the predetermined threshold value Th8 (step S313). As a result of the determination, if the value of the average information data length 159 is smaller than the threshold value Th8, it is determined that the frequency band is not changed, and the process C6 is terminated.
On the other hand, when the average information data length 159 is the threshold value Th8 or more, the control unit 15 refers to the frequency usable flag 156 of the frequency detection result storage unit 152 and determines whether or not there is a changeable frequency band. .. That is, if the frequency usable flags 156 of all frequency bands F1, ..., Fm are referred to and all the frequency usable flags 156 are "0", there is no changeable frequency band and the frequency is used. If there is at least one frequency band for which the enable flag 156 is "1", it is determined that there is a changeable frequency band (step S314). As a result of this determination, if there is no changeable frequency band, it is determined that the frequency band is not changed, and the process C6 is terminated.
On the other hand, when it is determined that the frequency band that can be changed exists, the control unit 15 determines to change the frequency band (step S315). At this time, as shown in FIG. 6, when the frequency band Fi in which the frequency enable flag 156 is 1 is only F3, the control unit 15 determines to use the frequency band F3 after the change. To do. When the plurality of frequency usable flags 156 are set to "1", the control unit 15 refers to the frequency detection result storage unit 152, and the frequency band having the largest bandwidth for communication with the mobile station 201. Decide to use Fi.
That is, in this evaluation process C6, the communication status of mobile stations 201, 202, ... Is evaluated, and when there is a mobile station that frequently communicates a large amount of information data, the most available frequency band is available. The frequency band is changed so that communication is performed using the frequency band Fi, which has a large bandwidth.
As described above, according to the third embodiment, the same effect as that of the first embodiment can be obtained, and there is a mobile station communicating using the frequency band FC, and the base station apparatus 100 When the control unit 15 decides to select one of a plurality of frequency bands to change the frequency band used for communication with this mobile station, communication with the mobile station exchanging a small amount of information data. By selecting the frequency band with the lowest bandwidth, and by selecting the frequency band with the highest bandwidth for communication with mobile stations that frequently exchange large amounts of information data, the second radio The frequency bands F1, F2, ..., Fm assigned to the communication system,<u style="single">Prevents long-term use,</u>The interference given to the second wireless communication system can be further reduced.
The present invention is not limited to the above-described embodiment as it is, and at the implementation stage, the components can be modified and embodied within a range that does not deviate from the gist thereof. In addition, various inventions can be formed by appropriately combining the plurality of components disclosed in the above examples. For example, some components may be removed from all the components shown in the examples. In addition, components across different embodiments may be combined as appropriate.
<figref num="1">The figure which shows the structure of the wireless communication system which concerns on 1st Example of this invention.</figref><figref num="2">The figure which shows the structure of the frequency band which concerns on 1st Example of this invention.</figref><figref num="3">The block diagram which shows the structure of the base station apparatus 100 which concerns on 1st Embodiment of this invention.</figref><figref num="4">The figure which shows the structure of the frequency allocation storage part 151 of the base station apparatus 100 which concerns on 1st Embodiment of this invention.</figref><figref num="5">The figure which shows the structure of the frequency detection storage part 152 which concerns on 1st Example of this invention.</figref><figref num="6">The figure which shows the structure of the communication state storage part 153 which concerns on 1st Embodiment of this invention.</figref><figref num="7">The block diagram which shows the structure of the mobile station 201 which concerns on 1st Embodiment of this invention.</figref><figref num="8">The figure which shows the structure of the frequency allocation storage part 26 of the mobile station 201 which concerns on 1st Embodiment of this invention.</figref><figref num="9">The figure which shows the sequence of the wireless communication between the base station apparatus 100 and the mobile station 201 which concerns on 1st Embodiment of this invention.</figref><figref num="10">The flowchart which shows the flow of the frequency detection process A which concerns on 1st Embodiment of this invention.</figref><figref num="11">The flowchart which shows the flow of the frequency change evaluation process B1 which concerns on 1st Embodiment of this invention.</figref><figref num="12">The flowchart which shows the flow of the evaluation process C1 which concerns on 1st Example of this invention.</figref><figref num="13">The flowchart which shows the evaluation process C2 which concerns on 1st Example of this invention.</figref><figref num="14">The flowchart which shows the evaluation process C3 which concerns on 1st Example of this invention.</figref><figref num="15">The flowchart which shows the flow of the frequency change evaluation process B2 which concerns on the 2nd Embodiment of this invention.</figref><figref num="16">The flowchart which shows the flow of utilization efficiency evaluation process D1 which concerns on 2nd Example of this invention.</figref><figref num="17">The flowchart which shows the flow of utilization efficiency evaluation process D2 which concerns on 2nd Example of this invention.</figref><figref num="18">The flowchart which shows the flow of utilization efficiency evaluation process D3 which concerns on 2nd Example of this invention.</figref><figref num="19">The figure which shows the structure of the communication state storage part 153 which concerns on the 2nd Example of this invention.</figref><figref num="20">The figure which shows the structure of the frequency band which concerns on 3rd Example of this invention.</figref><figref num="21">The figure which shows the structure of the frequency detection storage part 160 which concerns on 3rd Example of this invention.</figref><figref num="22">The flowchart which shows the flow of the evaluation process C4 which concerns on the 3rd Example of this invention.</figref><figref num="23">The flowchart which shows the flow of the evaluation process C5 which concerns on the 3rd Example of this invention.</figref><figref num="24">The flowchart which shows the flow of the evaluation process C6 which concerns on the 3rd Example of this invention.</figref>
Code description
11,12-1, , 12-N, 21,22 Wireless communication circuit 13,14,23,24 Control circuit 15,25 Control unit 111,112,121-1,122-1,211,212,221,222 Antenna 113,114,123-1,124-1,213,214,223,224 Wireless processing circuit 115,125-1,215,225 Modulation circuit 116,126-1,216,226 Demodulation circuit 127-1 Frequency detection circuit 151,251 Frequency allocation storage 152 Frequency detection result storage unit 153 Communication status storage unit
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| Document | Relation | Office |
|---|---|---|
| JP2003333648A | Cites | Japan |
4 members in 2 offices
Priority claims2
| Document | Office | Kind | Date |
|---|---|---|---|
| 2006020812 | Japan | A | |
| JP20060020812 | – | – | – |
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| Document | Office | Kind | |
|---|---|---|---|
| US2007178840A1 | United States of America | A1 | |
| JP2007202039A | Japan | A | |
| US7912110B2 | United States of America | B2 | |
| JP4685646B2This record | Japan | B2 |
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Numbers
- Publication
- 4685646
- Publication, DOCDB
- 4685646
- Publication, EPODOC
- JP4685646B
- Application
- 20812
- Application, DOCDB
- 2006020812
- Application, EPODOC
- JP20060020812
Titles2
- Japanese
- 基地局装置及び無線通信システム及び周波数割当方法
- English
- Base station equipment and wireless communication system and frequency allocation method
Classification
- CPC, 5
- H04W88/10
- H04W16/14
- H04W28/16
- H04W72/0453
- H04W74/0808
- IPC, 4
- H04W16 14
- H04W72 08
- H04W72 04
- H04W88 10