3. The near-term model: a hybrid fiber/5G-based converged power grid-communication networking infrastructure

The near-term model utilizes public commercial 5G cellular network and technologies along with public commercial PON-based fiber-to-the-Node/Home (FTTN/FTTH) residential access network.

The evolving 5G cell-based network technologies are the core of the anticipated architecture. This architecture utilizes LTE-A equipped M2M communications and HetNet infrastructure as the solitary cellular technology that effortlessly extending from HAN to NAN to MAN to global. Moreover, the projected architecture uses an affordable fiber-dependent SC backhaul infrastructure, which exploits the present fibered services linked with a PON-dependent FTTH/FTTN domestic access network. Consequently, the projected hybrid-networking infrastructure implies the fiber network reliability and the community cell-based network flexibility.

The projected community cell-based network allows utilities to wirelessly connect to the universal distribution grid assets. Assets comprising smart meters, smart home appliances, PEV charging infrastructure, microgrids, substations, feeders (connected from substations to the client location), circuit breakers, transmission towers, and mobile workforce. Related to the grid assets, there is at least one costeffective static embedded chip set (LTE-A equipped M2M unit), or mobile in the case of PEVs, that transmits and collects data to/from the macro-BSs, micro-BSs, or another M2M unit. The direct M2M communications is merely necessary in the

HANs and microgrid/PEVs. On the other hand, the communications among the other M2M components are dedicated for data forwarding only.

Per 3GPP standard, LTE/LTE-A comprises of an improved BS called evolved NodeB (eNB) and a mobile CN called evolved packet core (EPC) on the core side. Basically, EPC logical components comprises of mobility management entity (MME) in the control plane. On the other hand, the bearer plane is composed of the serving gateway (S-GW) and the packet data network gateway (P-GW). Practically, as one physical network defined as access gateway (A-GW), both gateways can be implemented based on vendor support and deployment scenarios [11]. The collected control and monitoring traffic is processed by the manager and then transmits the commands back to the DERMSi manager. The manager may forward these data before and/or after processing it to the control center and utility data.

### 3.1 Proposed hybrid fiber-based & LTE-A enabled HetNet & M2M communications architecture

Figure 2 illustrates the proposed architecture covering a utility's service territory in the coverage zone of a single macro-BS and numerous micro-BSs. Macro-BS coverage area may be extended to include at least one substation that are adjacent electrically, connected to the same node on the transmission system (necessary to regulate the power network), smart grid assets, as well as electric storage. Utility control, data center(s), headquarters, enterprise office locations, bulk power locations (owned by the utility), optical line terminal (OLT), EPC, and M2M application server, are all connected through dedicated fiber links.

A Public microgrid DERMSi manager is assembled with each optical network unit (ONU), which receives control data traffic from a group of public microgrid's central controllers (MGCC). In other words, LTE-A equipped M2M modules

Figure 2. The schematic diagram of the proposed architecture.

#### xIoT-Based Converged 5G and ICT Infrastructure DOI: http://dx.doi.org/10.5772/intechopen.97605

through the SC serving these constellations and/or through direct M2M communications if they are positioned inside the acceptable contiguity distance identified by LTE-A standards. The received monitoring and control data is processed by DERMSi manager and returns the commands to the group of MGCC. While the second higher level DERMSii central manager is positioned with the (OLT) at the central office (CO), which collects the grid's control traffic from the first level DERMSi managers through the fiber dependent PON infrastructure for higher reliability. The received control data are processed by the DERMSii central manager and then broadcasts the commands to the DERMSi manager. DERMSii may also forward these data and/or after processing it to the utility data and the control center(s). The direct wired fiber-dependent communications between the DERMSii central manager and the first level DERMSi manager is significantly highly reliable, which guarantee swift delivery of the critical mission control data. It is noted that MGCCs and DERMSii can decide to bypass the first level DERMSi managers and communicate directly through the PON and HetNet. Because the DERMSii central manager has a universal knowledge of the entire local distribution grid's portion assets inside this specified domestic zone, it can manage, and control the whole distribution grid applications in this local portion. For example, efficient energy management and optimization models development, advanced metering, demand response (DR), smart electric Vehicle (EV) charging, and distributed generation. It is noted that the anticipated architecture supports the flexibility of supporting such management and control operations either in an entirely integrated method, an entirely distributed method, or a hybrid method that uses both approaches.

Additionally, the CO can accommodate numerous OLTs, and each OLT can operate more than one PON and, hence, at least one DERMSii central manager may be accommodated at the CO. Domestic NAN/FAN architecture may be extended to a worldwide scale widening from NAN to MAN to WAN to a universal would span several interconnected COs. At each CO, all instantaneous monitoring and control traffic will be efficiently processed and forwarded by a group of DERMSii central manager and then collected from all communication endpoints, which are served by several PONs and HetNets. The instantaneous knowledge of the whole universal grid status and assets will be identified significantly by the utility data and control centers. This provides the power grid with the potential of self-healing capability, efficient resilience, reliability, and survivability mechanisms.

#### 3.2 PON-based SC backhaul infrastructure

A new challenge for the backhaul is introduced by an extensive implementation of SC, which must support connections at enough capacity and assured quality of service (QoS). The quantity of SC sites in a specific macrocell zone can grow up to numerous hundreds (e.g., large city center). All SC necessitate fast backhaul connection. Consequently, the connection implementation between the mobile CN and the SC BSs becomes challenging. The key challenge is how to provide cost-effective, scalable and flexible mobile backhaul solution to connect a massive number of SCs to the mobile CN. To tackle the backhauling challenge, I propose and utilize an economical fiber-based SC backhaul infrastructure, which exploits the current fiber facilities connected to a PON-based FTTN/FTTH domestic access network [12–14]. Due to the distribution of the current fiber assets, the projected PON–based backhaul architecture, in which the SCs are housed with the present FTTN remote units (ONUs) is much more cost-effective than traditional cost prohibitive P2P fiber backhaul schemes.

The HetNet backhaul RAN architecture could be developed from the PON architecture essentially by superimposing the SCs with the ONUs, while exploiting the available present fiber backhaul over dark fibers and operated ONUs linked with the PON-dependent FTTx domestic access network. The SCs is implemented using a low-height (2–4 m) antenna affixed on or adjacent to the ONU (e.g., near to a light post). The CO accommodates the OLT, which links with metro/EPC through the metro terminal equipment located at the CO. The PON and LTE-A based SC systems are autonomously operated where the HetNet RAN system is expected to have its own management and control functions independently from the PON. Each SC is expected to be positioned with an ONU or treated as a generic user attached to it. The ONU and SC can be communicated as long as they support a common standard interface. Consequently, the OLT, EPC, ONUs, and SCs, are completely anticipated to provide a common standard interface (e.g., 802.3ah Ethernet interface). [13, 14]. Each ONU is expected to have two diverse Ethernet port ranges; the first port range will support wired users, while the second one will support wireless M2M grid traffic. The port ranges will be used by the ONUs to identify and differentiate between wireless M2M grid traffic versus typical PON fixed users.

A tight coordination and cooperation between the utilities and telecom carriers or preferably an integrated power-grid-communication network is required in order to reap the full benefits of such hybrid architecture. Because power and communications companies are generally separate commercial enterprises in North America and Europe, implementing this vision will require considerable government and large-vendor effort to encourage various enterprises to cooperate. In any case, utilizing public, commercial mobile and FTTN/FTTH residential access networks for smart grid requires tight coordination and cooperation between both parties. Given the utmost importance of the power grid for the welfare and national security of the nation, integrating these two sectors should be given highest priority.
