Abstract: This invention provides a current self-checking regulation circuit based on voltage calibration including a bandgap reference unit, a self-calibration unit, a detection and regulation unit, current mirror units, and a current mirror control unit. The bandgap reference unit is configured to generate a voltage signal, the self-calibration unit is configured to respond to a digital signal of the detection and regulation unit and calibrate the voltage signal of the bandgap reference unit. The detection and regulation unit samples the reference current signal and a mirror current signal of the regulation group current mirror unit and generate a digital control signal according to the reference current signal. and the reference group current mirror unit responds to the digital control signal and outputs a regulated bias current signal meeting needs of the laser driver.

Abstract: This invention provides a multi-bit digitally controlled accurate current source circuit including a reference current detection unit, a voltage buffer unit, a digital logic control unit, a switch array unit, and a current source array unit. The reference current detection unit generates a first bias voltage according to a reference current; the voltage buffer unit receives the first bias voltage, and generate a buffer voltage accordingly; the digital logic control unit receives the buffer voltage, and generate a digital control signal accordingly; the switch array unit receives the digital control signal, and generate on-off signals accordingly; and the current source array unit receives and responds to the on-off signals so as to control turn-on and turn-off of the current sources in the current source array unit. In this invention, by adding only one voltage buffer, a cascode current source if formed, and an area saving accurate current source is realized.

Abstract: This invention provides a relaxation oscillator, including a first comparator, a second comparator, an SR latch, and a capacitor control module. Input ends of the two comparators are coupled with the capacitor control module and an external reference threshold voltage, and two output ends are coupled with the input ends of the SR latch; output ends of the SR latch are coupled with input ends of the capacitor control module; According to the external reference threshold voltage, a first comparison signal generated by the first comparator and a second comparison signal generated by the second comparator are inputted into the SR latch to generate a control signal. According to a bias current of the external bias current source and the control signal outputted by the SR latch, periodic charging and discharging of a first capacitor and a second capacitor are controlled to generate oscillating signals.

Abstract: System and method for mobile network access load balancing. In accordance with a first method embodiment, a method includes receiving, at a network access load balancing controller, performance status information from a mobile network access gateway. The method also includes calculating, at the network access load balancing controller, a dynamic performance score for the mobile network access gateway utilizing the performance status information and calculating, at the network access load balancing controller, a weighted ranking of dynamic performance scores of a plurality of mobile network access gateways. The method further includes assigning, based on the weighted ranking of dynamic performance scores, one of the plurality of mobile network access gateways to serve as a mobile network access gateway for a user element.

Abstract: This invention provides a multi-bit digitally controlled accurate current source circuit including a reference current detection unit, a voltage buffer unit, a digital logic control unit, a switch array unit, and a current source array unit. The reference current detection unit generates a first bias voltage according to a reference current; the voltage buffer unit receives the first bias voltage, and generate a buffer voltage accordingly; the digital logic control unit receives the buffer voltage, and generate a digital control signal accordingly; the switch array unit receives the digital control signal, and generate on-off signals accordingly; and the current source array unit receives and responds to the on-off signals so as to control turn-on and turn-off of the current sources in the current source array unit. In this invention, by adding only one voltage buffer, a cascode current source if formed, and an area saving accurate current source is realized.

Abstract: This invention provides a current self-checking regulation circuit based on voltage calibration including a bandgap reference unit, a self-calibration unit, a detection and regulation unit, current mirror units, and a current mirror control unit. The bandgap reference unit is configured to generate a voltage signal, the self-calibration unit is configured to respond to a digital signal of the detection and regulation unit and calibrate the voltage signal of the bandgap reference unit. The detection and regulation unit samples the reference current signal and a mirror current signal of the regulation group current mirror unit and generate a digital control signal according to the reference current signal. and the reference group current mirror unit responds to the digital control signal and outputs a regulated bias current signal meeting needs of the laser driver.

Abstract: This invention provides a relaxation oscillator, including a first comparator, a second comparator, an SR latch, and a capacitor control module. Input ends of the two comparators are coupled with the capacitor control module and an external reference threshold voltage, and two output ends are coupled with the input ends of the SR latch; output ends of the SR latch are coupled with input ends of the capacitor control module; According to the external reference threshold voltage, a first comparison signal generated by the first comparator and a second comparison signal generated by the second comparator are inputted into the SR latch to generate a control signal. According to a bias current of the external bias current source and the control signal outputted by the SR latch, periodic charging and discharging of a first capacitor and a second capacitor are controlled to generate oscillating signals.

Abstract: A method and system for selecting a server load balancer (SLB) for processing requests associated with a client are provided. The method may commence with receiving a Domain Name System (DNS) request from a client DNS server associated with the client. The method may include determining a geolocation of the client. The method may continue with receiving a time delay record including a round trip time (RTT) between the client and each of pluralities of SLBs and a geolocation of each SLB. The method may include matching the geolocation of the client and the geolocation of each of the pluralities of SLBs. The method may include selecting SLBs having the geolocation that matches the geolocation of the client. The method may further include selecting, from the SLBs, an SLB having a lowest RTT and sending a DNS response comprising network data of the selected SLB to the client DNS server.

Abstract: Provided are methods and systems for managing health statuses of servers. The method for managing health statuses of servers in a distributed GSLB system may include receiving, at a GSLB site controller, health statuses of local servers associated with the GSLB site controller. The method may further include exchanging, by the GSLB site controller, the health statuses of the local servers with health statuses of remote servers associated with at least one remote GSLB site controller. The method may further include distributing, by the GSLB site controller, at least a part of the health statuses of the local servers and the remote servers to SLBs associated with the GSLB site controller.

Abstract: Provided are methods and systems for managing health statuses of servers. The method for managing health statuses of servers in a distributed GSLB system may include receiving, at a GSLB site controller, health statuses of local servers associated with the GSLB site controller. The method may further include exchanging, by the GSLB site controller, the health statuses of the local servers with health statuses of remote servers associated with at least one remote GSLB site controller. The method may further include distributing, by the GSLB site controller, at least a part of the health statuses of the local servers and the remote servers to SLBs associated with the GSLB site controller.

Abstract: A method and system for measuring application response delay is described. The method may commence with receiving a Domain Name System (DNS) request from a client DNS server. The method may include measuring round trip time between the client DNS server and a first Global Server Load Balancing (GSLB) controller, between the first GSLB controller and a server load balancer (SLB) collocated with the first GSLB controller, and between the SLB and an application server. The method may further include receiving measurements of round trip time between the client DNS server and a second GSLB controller, between the second GSLB controller and an SLB collocated with the second GSLB controller, and between the second GSLB controller and a further application server. A cumulative response time associated with the application servers may be calculated based on the measurements to select an application server having a lowest cumulative response time.

Abstract: System and method for mobile network access load balancing. In accordance with a first method embodiment, a method includes receiving, at a network access load balancing controller, performance status information from a mobile network access gateway. The method also includes calculating, at the network access load balancing controller, a dynamic performance score for the mobile network access gateway utilizing the performance status information and calculating, at the network access load balancing controller, a weighted ranking of dynamic performance scores of a plurality of mobile network access gateways. The method further includes assigning, based on the weighted ranking of dynamic performance scores, one of the plurality of mobile network access gateways to serve as a mobile network access gateway for a user element.

Abstract: A method and system for selecting a server load balancer (SLB) for processing requests associated with a client are provided. The method may commence with receiving a Domain Name System (DNS) request from a client DNS server associated with the client. The method may include determining a geolocation of the client. The method may continue with receiving a time delay record including a round trip time (RTT) between the client and each of pluralities of SLBs and a geolocation of each SLB. The method may include matching the geolocation of the client and the geolocation of each of the pluralities of SLBs. The method may include selecting SLBs having the geolocation that matches the geolocation of the client. The method may further include selecting, from the SLBs, an SLB having a lowest RTT and sending a DNS response comprising network data of the selected SLB to the client DNS server.

Abstract: A method and system for measuring application response delay is described. The method may commence with receiving a Domain Name System (DNS) request from a client DNS server. The method may include measuring round trip time between the client DNS server and a first Global Server Load Balancing (GSLB) controller, between the first GSLB controller and a server load balancer (SLB) collocated with the first GSLB controller, and between the SLB and an application server. The method may further include receiving measurements of round trip time between the client DNS server and a second GSLB controller, between the second GSLB controller and an SLB collocated with the second GSLB controller, and between the second GSLB controller and a further application server. A cumulative response time associated with the application servers may be calculated based on the measurements to select an application server having a lowest cumulative response time.