CN114765704A - Home base station network system and uplink transmission bandwidth allocation method applied to same - Google Patents

Abstract

The invention provides a home base station network system and an uplink transmission bandwidth allocation method applied to the same, belonging to the technical field of communication, wherein the home base station network system comprises: the system comprises an indoor baseband processing unit, a radio remote unit and a passive optical network; one end of the indoor baseband processing unit is connected with a core network, and the other end of the indoor baseband processing unit is connected with the first end of the passive optical fiber network; the second end of the passive optical fiber network is connected with the remote radio unit; the remote radio unit is used for realizing wireless receiving and transmitting. The invention provides a fronthaul PON-based extended home base station networking scheme, which can realize that a plurality of households share one cell, solve the problem of same frequency interference among households of the integrated home base station scheme, improve user experience, reduce the number of cells, facilitate core network management, and realize rapid deployment by utilizing a deployed broadband PON network.

Description

Home base station network system and uplink transmission bandwidth allocation method applied to same

Technical Field

The present invention relates to the field of communications technologies, and in particular, to a femtocell network system and an uplink transmission bandwidth allocation method applied thereto.

Background

At present, in a home scene, the problems of weak signals, poor network and the like generally exist, and along with the diversified development of home scene services, the requirement of a user on the network is higher and higher, so that the enhancement of home coverage and the improvement of network quality are very important. Referring to fig. 1, an integrated station (femto) is mostly adopted in an existing home station, and meanwhile, radio frequency transceiving and base station protocol stack processing functions are realized, a deployed broadband Passive Optical Network (PON) Network is utilized on a networking to realize data return with a core Network, an access side is connected with an Optical Network Unit (ONU) through a Network cable, and rapid deployment can be realized for a home with a demand.

In the existing household integrated small station scheme, home equipment is an integrated base station, backhaul is realized by using a PON (passive optical network), each household monopolizes one cell, co-frequency interference between households is difficult to solve, user experience is influenced, and in addition, the number of cells also causes complex core network management.

Disclosure of Invention

In view of this, the present invention provides a femtocell network system and an uplink transmission bandwidth allocation method applied thereto, which are used to solve the problems of co-channel interference and complex core network management caused by a large number of cells in the current home integrated cell scheme.

To solve the above technical problem, in a first aspect, the present invention provides a home base station network system, including: the system comprises an indoor baseband processing unit, a radio remote unit and a passive optical network;

one end of the indoor baseband processing unit is connected with a core network, and the other end of the indoor baseband processing unit is connected with the first end of the passive optical fiber network;

the second end of the passive optical fiber network is connected with the remote radio unit;

the remote radio unit is used for realizing wireless receiving and transmitting.

Optionally, the passive optical network includes an optical line terminal, an optical distribution network, and an optical network unit;

one end of the optical line terminal, which is used as the first end of the passive optical fiber network, is connected with the indoor baseband processing unit, and the other end of the optical line terminal is connected with one end of the optical distribution network;

the other end of the optical distribution network is connected with one end of at least one optical network unit;

and the other end of the optical network unit is used as a second end of the passive optical network and connected with the remote radio unit.

Optionally, the indoor baseband processing unit is configured to implement a layer two and a layer three function of the base station;

the remote radio unit is used for realizing the layer one and the medium radio frequency functions of the base station.

In a second aspect, the present invention further provides an uplink transmission bandwidth allocation method, which is applied to any one of the home base station network systems in the first aspect, where the method includes:

the remote radio unit analyzes uplink resource allocation information sent to the terminal by the indoor baseband processing unit and calculates uplink required bandwidth information;

and the radio remote unit sends the uplink required bandwidth information obtained by calculation to a passive optical network for bandwidth allocation.

Optionally, the passive optical network includes an optical line terminal, an optical distribution network, and an optical network unit; one end of the optical line terminal, which is used as the first end of the passive optical fiber network, is connected with the indoor baseband processing unit, and the other end of the optical line terminal is connected with one end of the optical distribution network; the other end of the optical distribution network is connected with one end of at least one optical network unit; the other end of the optical network unit is used as a second end of the passive optical network and connected with the remote radio unit;

the radio remote unit sends the uplink required bandwidth information obtained by calculation to a passive optical network for bandwidth allocation, and the bandwidth allocation comprises the following steps:

the remote radio unit sends the uplink required bandwidth information to the optical network unit;

the optical network unit sends bandwidth allocation request information to the optical line terminal according to the uplink required bandwidth information;

and the optical line terminal determines the bandwidth information allocated to the optical network unit according to the bandwidth allocation request information.

Optionally, after the determining, by the optical line terminal according to the bandwidth allocation request information, bandwidth information allocated to the optical network unit, the method further includes:

the optical line terminal sends the bandwidth information to the optical network unit;

and after receiving the uplink data which is sent by the terminal and forwarded by the remote radio unit, the optical network unit sends the uplink data to the optical line terminal according to the bandwidth information.

Optionally, the data packet sent by the remote radio unit to the optical network unit includes packet header information;

the packet header information comprises a type field and a bandwidth field;

the type field is used for indicating whether the information type carried by the data packet is the uplink required bandwidth information or the uplink data.

Optionally, the data packet further includes an effective data field, where the effective data field is used to carry the uplink data.

Optionally, before the remote radio unit analyzes uplink resource allocation information sent by the indoor baseband processing unit to the terminal and calculates uplink required bandwidth information, the method further includes:

and the indoor baseband processing unit sends the uplink resource allocation information to the terminal through the radio remote unit according to the uplink scheduling request of the terminal.

The technical scheme of the invention has the following beneficial effects:

the embodiment of the invention provides a forward PON-based extended home base station networking scheme, which can realize that a plurality of households share one cell, solve the problem of same-frequency interference among households of the integrated home base station scheme, improve user experience, reduce the number of cells, facilitate core network management, and realize rapid deployment by utilizing a deployed broadband PON.

In addition, in the embodiment of the present invention, the radio remote unit calculates the uplink bandwidth demand information by analyzing the uplink resource allocation information sent by the indoor baseband processing unit (specifically, the base station scheduler) to the terminal, and then sends the uplink bandwidth demand information to the passive optical network to trigger bandwidth allocation, instead of triggering bandwidth allocation after the terminal analyzes the uplink resource scheduled by the downlink channel, sends uplink data to the RRU on the analyzed uplink resource, and the RRU receives the uplink data and performs physical layer processing and then sends the uplink data to the passive optical network, that is, the uplink bandwidth allocation flow is advanced. And when the radio remote unit analyzes uplink resource allocation information sent to the terminal by the indoor baseband processing unit, the uplink required bandwidth information is calculated, the calculated uplink required bandwidth information is sent to the passive optical network for bandwidth allocation, and the terminal still receives the uplink resource allocation information and analyzes the uplink resource allocation information and sends uplink data in a scheduled uplink time slot. That is to say, uplink bandwidth allocation and base station uplink service transmission are processed in parallel, so that uplink forwarding delay of a forwarding PON-based extended (distributed) home base station network system can be reduced.

Drawings

Fig. 1 is a schematic diagram of a conventional femtocell network system deployed based on a PON network;

fig. 2 is a schematic structural diagram of a home base station network system according to an embodiment of the present invention;

fig. 3 is a schematic structural diagram of another femtocell network system in an embodiment of the present invention;

fig. 4 is a schematic flowchart of a conventional uplink service transmission;

fig. 5 is a flowchart illustrating an uplink transmission bandwidth allocation method according to an embodiment of the present invention;

fig. 6 is a schematic flow chart of uplink service transmission in the embodiment of the present invention;

fig. 7 is a schematic format diagram of an interface message between an RRU and an ONU in an embodiment of the present invention;

fig. 8 is a schematic diagram of interface message configuration between an RRU and an ONU when sending an uplink data packet in the embodiment of the present invention;

fig. 9 is a schematic diagram of interface message configuration between an RRU and an ONU when sending a Size packet in the embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the drawings of the embodiments of the present invention. It is to be understood that the embodiments described are only a few embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the description of the embodiments of the invention given above, are within the scope of protection of the invention.

Referring to fig. 2, fig. 2 is a schematic structural diagram of a femtocell network system according to an embodiment of the present invention, where the femtocell network system includes: an indoor Baseband processing Unit (BBU) 21, a Remote Radio Unit (RRU) 22, and a Passive Optical Network (PON) 23;

one end of the indoor baseband processing unit 21 is connected to a core network, and the other end is connected to a first end of the passive optical network 23; specifically, the BBU21 may be connected to a core network through a gateway;

a second end of the passive optical fiber network 23 is connected to the remote radio unit 22;

the remote radio unit 22 is used for implementing wireless transceiving.

In the embodiment of the invention, the home base station is composed of the BBU21 and the RRU22, the BBU21 is arranged at a local side, the RRU22 enters a home to jointly complete all functions of the base station, and the PON23 equipment is arranged between the BBU21 and the RRU22 to bear the forward transmission of the home base station. One BBU21 may connect multiple RRUs 22, and multiple RRUs 22 may be combined into one cell on the BBU21 side.

The embodiment of the invention provides a forward-transmission PON 23-based extended home base station networking scheme, which can realize that a plurality of households share one cell, solve the problem of same frequency interference among households in the integrated home base station scheme, improve user experience, reduce the number of cells, facilitate core network management, and realize quick deployment by utilizing a deployed broadband PON23 network.

Optionally, referring to fig. 3, the passive Optical fiber Network 23 includes an Optical Line Terminal (OLT) 231, an Optical Distribution Network (ODN) 232, and an Optical Network Unit (ONU) 233;

a first end of the optical line termination 231, which is the passive optical network 23, is connected to the indoor baseband processing unit 21, and the other end is connected to one end of the optical distribution network 232;

the other end of the optical distribution network 232 is connected to one end of at least one optical network unit 233;

the other end of the optical network unit 233 serves as a second end of the passive optical network 23 and is connected to the remote radio unit 22.

The optical distribution network 232 includes passive optical splitters and optical fibers.

Optionally, the indoor baseband processing unit 21 is configured to implement a layer two and a layer three function of the base station;

the remote radio unit 22 is used to implement the layer one and middle radio frequency functions of the base station.

The embodiment of the application also provides a function division scheme of the forward-transmission PON 23-based extended home base station. The fronthaul bandwidth is related to the functional partitioning of the BBU21 and the RRU 22. In order to improve the bandwidth utilization rate of the PON23 port, the forward bandwidth of the home station should be reduced as much as possible. Therefore, the BBU21 and the RRU22 adopted by the embodiment of the invention are divided into functions that the BBU21 realizes the base station layer two and layer three functions, and the RRU22 realizes the base station layer one (physical layer) and medium Radio Frequency (RF) functions, so as to reduce the requirement of the forward bandwidth.

The PON employs broadcast transmission in the downstream direction, and transmits data in the upstream direction by Time Division Multiplexing (TDMA), and the uplink is divided into different time slots. The process of sending the uplink service (specifically, the data of the uplink service, that is, the uplink data) of the femtocell is as follows: after receiving the uplink scheduling request of the access terminal, the base station scheduler sends the uplink transmission resource allocated to the access terminal in advance in the downlink time slot, and the terminal sends uplink data in the uplink time slot according to the allocation information. After receiving the upstream data, ONU233 initiates a bandwidth application to OLT231, OLT231 calculates a BWmap field value and carries bandwidth information allocated to ONU233, and all ONUs 233 transmit the upstream data in the allocated time slot.

Referring to fig. 4, generally, the main steps of the uplink service transmission of any femtocell network system in the first embodiment are as follows:

1. a base station scheduler sends uplink resource allocation information (also called scheduling information) in a Physical Downlink Control Channel (PDCCH);

2. a user performs downlink channel receiving processing, and transmits uplink data in an uplink time slot according to uplink resource allocation information (namely scheduling information);

3. the RRU22 receives the uplink data, performs physical layer processing, and sends the uplink data to the ONU 233;

4. the ONU233 buffers data and calculates a required bandwidth and reports the bandwidth to the OLT 231;

5. after calculating by an internal Dynamic Bandwidth Allocation (DBA) engine (engine) of the OLT231, a BWmap field is obtained and sent to the ONU233, which includes bandwidth allocation information;

6. ONU233 analyzes BWmap and transmits uplink data in the allocated timeslot.

In the uplink service transmission scheme in which the uplink bandwidth allocation of the PON23 and the uplink service transmission of the base station are processed in series, the delay generated by the information interaction between the OLT231 and the ONU233 in the uplink direction is introduced into the uplink forwarding of the home base station, that is, the total uplink delay is the sum of the uplink delay of the base station and the uplink bandwidth allocation introduction delay of the PON 23. If the PON23 is far away from the transmission distance, the delay introduced by the fronthaul interface may increase the transmission time between the MAC layer and the physical layer in the uplink direction, which may cause the number of scheduling processes of the home station to be limited, and affect the uplink performance of the home station. To address this problem, embodiments of the present invention provide the following uplink transmission bandwidth allocation scheme.

Referring to fig. 5, fig. 5 is a flowchart illustrating an uplink transmission bandwidth allocation method according to a second embodiment of the present invention, where the method is applied to any one of the femtocell network systems according to the first embodiment, and includes the following steps:

step 51: the remote radio unit 22 analyzes uplink resource allocation information sent to the terminal by the indoor baseband processing unit 21, and calculates uplink required bandwidth information;

after the terminal requests uplink resources from the indoor baseband processing unit 21 of the hnb according to the uplink data to be sent (i.e., sends an uplink scheduling request to the indoor baseband processing unit 21), the indoor baseband processing unit 21 allocates corresponding uplink resources according to the request of the terminal, and sends the uplink resources to the terminal through the radio remote unit 22. And the uplink required bandwidth information is matched with the bandwidth required by the terminal for transmitting the uplink data to be transmitted.

Step 52: the remote radio unit 22 sends the calculated uplink required bandwidth information to the passive optical network 23 for bandwidth allocation.

In the embodiment of the present invention, the radio remote unit 22 calculates the uplink bandwidth demand information by analyzing the uplink resource allocation information sent by the indoor baseband processing unit 21 (specifically, the base station scheduler) to the terminal, and then sends the uplink bandwidth demand information to the passive optical network 23 to trigger bandwidth allocation, instead of analyzing the uplink resource scheduled by the downlink channel at the terminal, sending uplink data to the RRU22 on the analyzed uplink resource, receiving the uplink data by the RRU22, performing physical layer processing on the uplink data, and then sending the uplink data to the passive optical network 23 to trigger bandwidth allocation, that is, the uplink bandwidth allocation flow is advanced. And, when the radio remote unit 22 analyzes the uplink resource allocation information sent by the indoor baseband processing unit 21 to the terminal, calculates uplink required bandwidth information, and sends the calculated uplink required bandwidth information to the passive optical network 23, and performs bandwidth allocation, while the terminal still receives the uplink resource allocation information, analyzes the uplink resource allocation information, and sends uplink data in a scheduled uplink timeslot. That is to say, the uplink bandwidth allocation and the base station uplink service transmission are processed in parallel, so that the uplink forwarding delay of the extended (distributed) home base station network system based on the PON23 can be reduced.

Optionally, before the remote radio unit 22 analyzes the uplink resource allocation information sent by the indoor baseband processing unit 21 to the terminal and calculates the uplink required bandwidth information, the method further includes:

the indoor baseband processing unit 21 sends the uplink resource allocation information to the terminal through the remote radio unit 22 according to the uplink scheduling request of the terminal.

Optionally, the passive optical network 23 includes an optical line terminal 231, an optical distribution network 232, and an optical network unit 233; a first end of the optical line termination 231, which is the passive optical network 23, is connected to the indoor baseband processing unit 21, and the other end is connected to one end of the optical distribution network 232; the other end of the optical distribution network 232 is connected to one end of at least one optical network unit 233; the other end of the optical network unit 233 is used as a second end of the passive optical network 23 and connected to the remote radio unit 22;

the remote radio unit 22 sends the calculated uplink bandwidth demand information to the passive optical network 23, and performs bandwidth allocation, including:

the remote radio unit 22 sends the uplink required bandwidth information to the optical network unit 233;

the optical network unit 233 sends bandwidth allocation request information to the optical line terminal 231 according to the uplink required bandwidth information;

the optical line terminal 231 determines bandwidth information allocated to the optical network unit 233 according to the bandwidth allocation request information.

Optionally, after determining the bandwidth information allocated to the optical network unit 233 according to the bandwidth allocation request information, the optical line terminal 231 further includes:

the optical line terminal 231 sends the bandwidth information to the optical network unit 233;

after receiving the uplink data sent by the terminal and forwarded by the remote radio unit 22, the optical network unit 233 sends the uplink data to the optical line terminal 231 according to the bandwidth information.

In the embodiment of the present invention, after receiving RRU22 uplink data, the ONU233 may directly use the BWmap information allocated by the OLT231 instead of starting the ONU233 bandwidth request process, which saves PON23 uplink bandwidth allocation time.

Referring to fig. 6, the main steps of sending the uplink service of any femtocell network system according to the first embodiment of the present invention are as follows:

1. a base station scheduler sends resource allocation information on a downlink PDCCH (physical downlink control channel);

2. the RRU22 analyzes uplink resource allocation information (i.e., scheduling information) of the access terminal at the downlink time slot, calculates a required uplink bandwidth, and sends the uplink required bandwidth information to the ONU 233;

3. the ONU233 initiates a bandwidth allocation request to the OLT231 in advance after receiving the bandwidth requirement;

4. after the DBA engine inside the OLT231 is calculated, a BWmap field is obtained and sent to the ONU233, which includes bandwidth allocation information;

5. the ONU233 stores BWmap field information;

in the step 2-5, the user performs downlink Channel receiving processing, and sends a Physical Uplink Shared Channel (PUSCH) in an Uplink time slot according to the scheduling information;

6. after receiving the uplink data from the RRU22, the ONU233 transmits the uplink data to the OLT231 at a specified time slot according to the bandwidth information allocated in the BWmap.

The embodiment of the invention saves the uplink bandwidth allocation time of the PON23 and solves the problem of time delay increase introduced by the PON 23.

Optionally, the data packet sent by the remote radio unit 22 to the optical network unit 233 includes packet header information;

the packet header information comprises a type field and a bandwidth field;

the type field is used for indicating whether the information type carried by the data packet is the uplink required bandwidth information or the uplink data.

Optionally, the data packet further includes an effective data field, and the effective data field is used for carrying the uplink data.

Because the existing interfaces between the ONU233 and the RRU22 only support data transmission and do not support the form of reporting bandwidth information by the RRU22 actively, a transmission interface message and a transmission method for adding the RRU22 and the ONU233 are needed.

An interface message of an extended home station RRU22 and an ONU233 based on PON23 is designed as follows: the RRU22 uplink transmission data (payload) may carry a header information (Head) with a format as shown in fig. 7, where the header information includes a Type field (Type) and a bandwidth field (Size). Type represents whether the current data packet is a Size packet: 1, the current data packet is a Size packet, the Size packet stores the number of uplink data bits, and the Payload field is invalid; 0: the current data packet is a data packet, Payload is uplink data, and the size field is empty.

Regarding the uplink data transmission method of the RRU22 of the extended home station based on the PON23, the RRU22 supports the following two uplink data transmission modes according to the configuration:

1. the RRU22 sends data according to the existing method, without reporting the Size packet, the interface message configuration is as shown in fig. 8, the type field and the bandwidth field are both 0, and the Payload field carries N bits uplink data.

2. The RRU22 actively reports the uplink bandwidth requirement, and two operations are required: the RRU22 sends the Size packet first and then sends the data packet. The interface message configuration when sending the Size packet is shown in fig. 9, where there is no Payload field. The interface message configuration when sending a data packet is shown in fig. 8.

The femtocell in the embodiment of the present invention may be a Base Transceiver Station (BTS) in Global System for Mobile communication (GSM) or Code Division Multiple Access (CDMA), may also be a Base Station (NodeB, NB) in Wideband Code Division Multiple Access (WCDMA), may also be an evolved Node B (evolved Node B, eNB or eNodeB) in LTE, or a relay Station or Access point, or a Base Station in a future 5G network, and the like, and is not limited herein.

A terminal in embodiments of the present invention may be a wireless terminal, which may be a device providing voice and/or other traffic data connectivity to a user, a handheld device having wireless connectivity, or other processing device connected to a wireless modem. A wireless terminal, which may be a mobile terminal such as a mobile telephone (or "cellular" telephone) and a computer having a mobile terminal, e.g., a portable, pocket, hand-held, computer-included, or vehicle-mounted mobile device, may communicate with one or more core networks via a Radio Access Network (RAN), and may exchange language and/or data with the RAN. For example, devices such as Personal Communication Service (PCS) phones, cordless phones, Session Initiation Protocol (SIP) phones, Wireless Local Loop (WLL) stations, and Personal Digital Assistants (PDAs) are used. A wireless Terminal may also be referred to as a system, a Subscriber Unit (Subscriber Unit), a Subscriber Station (Subscriber Station), a Mobile Station (Mobile), a Remote Station (Remote Station), a Remote Terminal (Remote Terminal), an Access Terminal (Access Terminal), a User Terminal (User Terminal), a User Agent (User Agent), and a Terminal (User Device or User Equipment), which are not limited herein.

While the foregoing is directed to the preferred embodiment of the present invention, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined in the appended claims.

Claims (9)

1. A home base station network system, comprising: the system comprises an indoor baseband processing unit, a radio remote unit and a passive optical network;

one end of the indoor baseband processing unit is connected with a core network, and the other end of the indoor baseband processing unit is connected with the first end of the passive optical fiber network;

the second end of the passive optical fiber network is connected with the remote radio unit;

the remote radio unit is used for realizing wireless transceiving.

2. The home base station network system according to claim 1, wherein the passive optical network comprises an optical line terminal, an optical distribution network and an optical network unit;

one end of the optical line terminal, which is used as the first end of the passive optical fiber network, is connected with the indoor baseband processing unit, and the other end of the optical line terminal is connected with one end of the optical distribution network;

the other end of the optical distribution network is connected with one end of at least one optical network unit;

and the other end of the optical network unit is used as a second end of the passive optical network and is connected with the remote radio unit.

3. The home base station network system according to claim 1 or 2, wherein the indoor baseband processing unit is configured to implement layer two and layer three functions of a base station;

the remote radio unit is used for realizing the first layer and the middle radio frequency functions of the base station.

4. An uplink transmission bandwidth allocation method applied to the home base station network system according to any one of claims 1-3, the method comprising:

the remote radio unit analyzes uplink resource allocation information sent to the terminal by the indoor baseband processing unit and calculates uplink required bandwidth information;

and the radio remote unit sends the uplink required bandwidth information obtained by calculation to a passive optical network for bandwidth allocation.

5. The method of claim 4, wherein the passive optical network comprises an optical line terminal, an optical distribution network, and an optical network unit; one end of the optical line terminal, which is used as the first end of the passive optical fiber network, is connected with the indoor baseband processing unit, and the other end of the optical line terminal is connected with one end of the optical distribution network; the other end of the optical distribution network is connected with one end of at least one optical network unit; the other end of the optical network unit is used as a second end of the passive optical network and connected with the remote radio unit;

the radio remote unit sends the uplink required bandwidth information obtained by calculation to a passive optical network for bandwidth allocation, and the bandwidth allocation comprises the following steps:

the remote radio unit sends the uplink required bandwidth information to the optical network unit;

the optical network unit sends bandwidth allocation request information to the optical line terminal according to the uplink required bandwidth information;

and the optical line terminal determines the bandwidth information allocated to the optical network unit according to the bandwidth allocation request information.

6. The method according to claim 5, wherein after the optical line terminal determines the bandwidth information allocated to the onu according to the bandwidth allocation request information, the method further comprises:

the optical line terminal sends the bandwidth information to the optical network unit;

and after receiving the uplink data which is sent by the terminal and forwarded by the remote radio unit, the optical network unit sends the uplink data to the optical line terminal according to the bandwidth information.

7. The method according to claim 6, wherein the data packet sent by the remote radio unit to the onu comprises header information;

the packet header information comprises a type field and a bandwidth field;

the type field is used for indicating whether the information type carried by the data packet is the uplink required bandwidth information or the uplink data.

8. The method of claim 7, wherein the data packet further comprises a valid data field, and wherein the valid data field is used for carrying the uplink data.

9. The method according to claim 4, wherein before the remote radio unit analyzes the uplink resource allocation information sent by the indoor baseband processing unit to the terminal and calculates the uplink required bandwidth information, the method further comprises:

and the indoor baseband processing unit sends the uplink resource allocation information to the terminal through the radio remote unit according to the uplink scheduling request of the terminal.

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