3GPP(3rd generation partnership project) — Development & maintenance: GSM(global system for mobile communications) & 2G, 2.5G, including GRPS(general packet radio service) & EDGE(enhanced data rates for GSM evolution) UMTS(universal mobile telecommunications system) & 3G, including HSPA(high speed packet access) & HSPA+ LTE(long-term evolution) & 4G, including LTE advanced & LTE advanced pro 5G NR(new radio)…

repo & Git repo: 管理git repository 格式: repo COMMAND OPTIONS repo help COMMAND repo init -u URL 在目前目錄安裝下載整個Android repository，會下建立一個”.repo”的目錄。 -u : 參數用來指定一個URL，從這個URL中獲取repository的manifest文件。 -m：用 …

ref: 黃婷婷課程, 杰哥 Pipeline: the continuous and somewhat overlapped movement of instruction to the processor or in the arithmetic steps taken by the processor to perform an instruction. ex: Split Single-cycle Datapath into 5 Steps, overlap the steps 沒有pipeline: 四個人要洗衣服，步驟有洗衣服 30min、烘衣服 40min、摺衣服 20min，如果大家輪流做，並且全部做完才輪到下一個人. 洗衣機, 烘衣機都有很長的idle時間 pipeline:

boot flow — Which bootloader the sys use sudo dd if=/dev/sda bs=512 count=1 2>/dev/null | strings | grep -Eoi ‘grub|lilo|acronis|reboot’ bootm -> kernel bootstrap介紹 Linux system須具備: 1. Bootloa …

control plane vs data plane: control plane: how data are forwarded, create routing table data(forwarding) plane: actually forwards the data SDN/NFV : Software-Defined Network(SDN):將路由器的control plane從data plane中分離，改以軟體方式實作，集中化管理分散在各個網路裝置上的control plane, 不更動硬體裝置的前提下，用軟體重新規劃網路 Network Functions Virtualization(NFV): 將實體設備的網路功能，以軟體的型態呈現，例如路由器（Router）、防火牆（Firewall）、負載平衡器（Load Balancer）與用戶終端設備（CPE）等

SONiC: — open source network operating system based on Linux that runs on switches from multiple vendors and ASICs SAI (Switch Abstraction Interface) SAI accept by the Open Compute Project (OCP) as a standardized C API to program ASICs. ref: Switch Abstraction Interface (SAI) officially accepted by the Open Compute Project (OCP) | Azure… As of July 2015, the Switch Abstraction Interface (SAI) specification has been officially accepted by the Open Compute…azure.microsoft.com