Sivers IMA announced the acquisition of CST Global in April 2017. When we announced the acquisition we also promised to share more details about the optical communication market which is one of several products areas CST Global offers solutions. In this post, we will focus on FTTH (fiber-to-the-home) which is part of the Fiber to the X (FTTX) market.
FTTX is the generic term for any broadband network architecture using optical fiber to provide all or part of the local loop used for last mile communication. FTTH is used to reach the boundary of the living space, such as a box on the outside wall of a home (i.e. the optical network terminal). To implement the last mile FTTH networks, passive optical networks are used to deliver for example end-user triple-play services over the network directly from an operator’s central network.
Passive optical network (PON) is a telecommunications technology that implements a point-to-multipoint architecture, in which unpowered fiber optical splitters are used to enable a single optical fiber to serve multiple end-points without having to provision individual fibers between the hub and customer. A PON consists of an optical line terminal (OLT) at the service provider’s central office (hub) and several optical network units (ONUs) or optical network terminals (ONTs), near end-users. A PON reduces the amount of fiber and central office equipment required compared to point-to-point architectures. A passive optical network is a form of fiber-optic access network to the home, a complement to Fixed Wireless Access (FWA), which is emphasizing on wireless access.
Figure 1: OLT/ONU/ONT Ref 
Each OLT normally connects to up 32 ONU or ONTs (see figure 1). CST Global offers optical laser chip products for both the first generation and second generation PON systems. The first generation ONU/OLT designs utilise 1310nm Fabry-Perot (FP) lasers. The second-generation system is the ITU standard Gigabit Passive Optical Network (GPON) which require the higher performing 1310nm Distributed Feedback (DFB) lasers to support higher data rates and longer link distances. CST Global has DFB lasers specified for the ITU 1.25 Gbps and 2.5 Gbps data rates. CST Global has shipped more than 35 million lasers to the world-wide PON ONU/OLT market and continues to increase capacity to meet increasing demand. The GPON downlink from the OLT requires a 1490nm laser diode at 2.5Gbps, as specified by the ITU standard. CST Global offers 1490nm, 2.5Gbps DFB laser for this application to provide an optical laser solution for the down link in addition to the higher volume up link device. On top of this, CST Global has a roadmap for 2017 for XPON (10G-PON), which is the latest generation 10 Gbps standard. On top of FTTX market, Nokia also sees 10G-PON as an important part of the future 5G transport/backhaul networks . This connects the CST products not just to Sivers IMA’s FWA offering but also to the future backhaul networks for 5G, where Sivers IMA’s mmWave products will be a complementary product to 10G-PON for backhaul for 5G networks, which further explains the strategic rationale for having access to both type of technologies.
According to Grand View Research (December 2016), the PON market is in a growth phase. In 2015, the total market was 5.8 Billion USD and will by 2025 be 43,5 Billion USD (see figure 2). This is equal to a CAGR of 22,2% until 2025.
As mentioned in blog about FWA, Ovum believes  FWA will compliment FTTX/FTTH for the future broadband subscription. See figure 3 below from Ovum, showing FTTX being more than 50% of the future broadband subscription (i.e. 500 Million) and FWA will be competing for the other 500 million of the worldwide market.
This sums up the potential for FTTH as well as explains parts of the the strategic rationale for the Sivers IMA’s acquisition of CST Global and the reasons why we see such great benefits having access to both optical and mmWave technologies.
Ref  https://www.slideshare.net/mansoor_gr8/gpon-fundamentals