Shanghai, China
Shanghai, China

Spreadtrum Communications, Inc. is a fabless semiconductor company headquartered in Shanghai, China which produces chipsets for mobile phones. It is the world's 17th-largest fabless semiconductor company measured by 2011 revenues.The company originally produced chips for GSM handsets, but most of its resources are now focused on the Chinese TD-SCDMA 3G standard. In addition to GSM and combined GSM/TD-SCDMA baseband chipsets, Spreadtrum also supplies chips for two Chinese mobile TV standards: TD-MBMS and CMMB. Spreadtrum's customers accounted for 50% of TD-SCDMA handset sales in China Mobile's current round of TD-SCDMA trials.In June 2008 the company's stock had fallen to a 52 week low owing to stalled sales, Later, the stock has increased steadily, reaching an all-time high in November 2011.Spreadtrum agreed an acquisition by Tsinghua Unigroup in July 2013 for about $1.78 billion; the deal completed on 23 December 2013. Wikipedia.


Time filter

Source Type

VoLTE based video calling method and device and a mobile terminal are provided. The method includes: receiving a request for VoLTE video calling from a user at a first UE; sending a session request message which carries a first video parameter supported by the first UE to a second UE through an EPS network; receiving a video QoS parameter sent by the EPS network; receiving a session response message sent through the EPS network by the second UE, the session response message carrying a second video parameter provided by the second UE which is determined based on the video QoS parameter and the first video parameter; determining a third video parameter for the first UE based on the video QoS parameter and the second video parameter; and initiating a VoLTE video calling using the third video parameter. Relatively good video calling quality may be obtained in different VoLTE networks.


Method and device for adjusting bit rate in video calling based on VoLTE, and mobile terminal are provided. The method includes: determining whether the data receiver transmits a TMMBR packet for the first time or has received a TMMBN packet from a data transmitter, or whether the number of times a same TMMBR packet has been retransmitted exceeds a predetermined time; if yes, estimating downlink reception bit rate and calculating downlink packet loss rate of RTP packet; calculating transmission bit rate of the data transmitter which is requested by the data receiver based on the estimated downlink reception bit rate and the calculated downlink packet loss rate of RTP packet; and transmitting the TMMBR packet to the data transmitter based on the transmission bit rate of the data transmitter. A bit rate can be dynamically adjusted based on actual network bandwidth, which may improve quality of video calling.


The present disclosure provides a method and device for transmitting a reference signal, a method and device for receiving the same, the transmitting method includes: determining a first antenna port for transmitting a demodulation reference signal and a second antenna port for transmitting an enhanced reference signal, where the second antenna port and the first antenna port have an association; setting a transmitting power for the demodulation reference signal and a transmitting power for the enhanced reference signal; transmitting the demodulation reference signal and the enhanced reference signal to a terminal based on the first antenna port being determined for transmitting the demodulation reference signal and the second antenna port being determined for transmitting the enhanced reference signal, and according to the transmitting powers being set. Accordingly, when present technical solution is applied, a channel estimation performance and a RRM measurement performance of a NB-IOT terminal can be effectively improved.


Patent
Spreadtrum Communications | Date: 2017-01-06

A data transmission method and a base station are provided. The method includes: setting up an RRC connection with a UE, and acquiring an information element for requesting C-SGN registration from a message transmitted by the UE during the setup of the RRC connection; transmitting an initial UE message to a connected C-SGN, wherein the C-SGN registers the UE based on the information element for requesting C-SGN registration contained in the initial UE message; after the UE registers to the C-SGN and data is received from the UE, transmitting the data to the C-SGN which then transmits the data to a destination address. By the method, signaling interaction during data transmission is reduced, which may improve efficiency of data transmission and reduce consumption of radio network resources.


Patent
Spreadtrum Communications | Date: 2016-12-28

Method for accessing cell and base station are provided. The method includes: transmitting system information indicating whether the cell supports connection resume function to a UE; after receiving an RRC connection resume request from the UE, acquiring a resume identification of the UE from the RRC connection resume request; looking up context information of the UE based on the resume identification, and transmitting an RRC connection resume acknowledgement message to the UE after finding the context information; after determining an MME supports connection resume function, transmitting a context information activation request including identification information of the UE to the MME; receiving a context information activation acknowledgement message from the MME, which is transmitted after the MME finds the context information of the UE according to the identification information; and transmitting a notification message indicating that a bearer is resumed to the UE. Failure in connection resume procedure is avoided.


First and second inputs are received. The first input indicates a frequency offset of a frequency band allocated for signal transmission. The said allocated band is a subband of a total band available for transmission. The second input indicates a bandwidth of the allocated band. One or more filters of a transmitter of a communications system are controlled to operate cumulatively in a lowpass filtering mode, wherein the highest frequency in a pass band in the lowpass filtering mode is less than the highest frequency of the total band available for transmission. A signal is filtered using the filter(s).


Patent
Spreadtrum Communications | Date: 2015-04-02

Method and apparatus for controlling a physical layer protocol data unit (PPDU) transmission rate of a physical layer in a first terminal are provided. The method includes: obtaining a media access control protocol data unit (MPDU) retransmission frequency of the first terminal in a first period, where the first terminal is a station or an access point in a wireless network; if the MPDU retransmission frequency is less than a frequency threshold, promoting the PPDU transmission rate in a second period; and else, suppressing the PPDU transmission rate in the second period, where the second period is following and adjacent to the first period along a time axis. The PPDU transmission rate may be adjusted adaptively according to a channels practical transmission state, the physical layer rate may be prevented from decreasing continuously in noisy channel environment, and a throughput rate may be improved in real time.


Method and apparatus for controlling startup of RTS/CTS mechanism is provided. The method includes: obtaining a noisy level of a channel based on the number of first data received by a first terminal in a first period, where the first terminal is a STA or an AP in a wireless network, and the first data include aggregation frames or non-aggregation frames; and if the noisy level is greater than or equal to a noisy level threshold, controlling the first terminal to start up the RTS/CTS mechanism when data is transmitted in a second period which is following and adjacent to the first period along a time axis. The noisy level of the channel may be obtained in real time, and the RTS/CTS mechanism may be controlled to be started up reasonably in real time, so that channel resources is utilized sufficiently, and a throughput rate is improved.


Method and apparatus for controlling length of aggregation frames in a wireless network is provided. The method includes: obtaining a noisy level of a channel based on the number of first data received by a first terminal in a first period, the first terminal being a STA or AP in the wireless network, and the first data include aggregation frames or non-aggregation frames; and determining length of an aggregation frame to be transmitted by the first terminal in a second period based on the noisy level, where the second period is following and adjacent to the first period along a time axis. The first terminal may detect the noisy level and select the length of the aggregation frame based on the noisy level. Thus, inter-frame collision and interference in the channel may be reduced, channel resources may be well utilized, and a throughput rate may be improved in real time.


A signal amplifying device and methods for control a signal amplifying device and for identifying a signal amplifying device are provided. The device includes: a baseband module, a user identification module interface, return side RF modules and antennas, access side RF modules and antennas. The return side antenna receives a downlink signal, which is transmitted to a corresponding access side RF module and the baseband module. An uplink signal is received by the access side antenna, which is transmitted to a corresponding return side RF module and the baseband module. The baseband module is adapted to process the uplink/downlink signal, control synchronization of the return side RF module and the access side RF module and control turning on and off of the same, read a user information. Accordingly, a cellular network can control a micro-power repeater effectively, and further more functionality can be added and performance can be improved.

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