FTTM Enables Rapid and Flexible LTE Deployment

Rapid LTE Growth

LTE is the fastest-growing technology in the history of mobile communications. With high bandwidth and low delay, LTE offers data rates far higher than those of existing wireless broadband networks. LTE ensures ubiquitous network coverage and seamless wireless applications.

Mobile traffic is experiencing explosive growth in the LTE era. To attract users, secure market share, and increase revenue, operators need to deploy many small cells to quickly boost network capacity, improve network coverage, offer superior user experience, and enhance market competitiveness. However, many small cells have an impact on bearer resources and cost.

PON FTTx Enables Fast, Low-Cost Small-Cell Deployment 

Small cells are usually carried over a public network. Mass small-cell deployment requires a network to have abundant mobile backhaul resources. The backhaul network must have high bandwidth; it must be very reliable; it must have accurate clock synchronization; and it must have flexible power supply. To generate revenue from the network, an operator has to select low-cost, flexible, reliable technology to backhaul the small cells. Existing widely deployed PON FTTx networks have inherent advantages in terms of carrying small cells.

Low-Cost Dense Coverage

Small cells are deployed more densely than existing macro cells. Therefore, it is unfeasible to use traditional backhaul platforms, which may also pose high requirements for uplink bandwidth of OLT ports. Moreover, the areas to be covered by small cells are largely the same as those covered by FTTx access networks. An FTTx access network can be used to quickly and flexibly deploy small cells. This enables quick return on investment, saves installment costs, and requires less bearer resources.

High-Precision Clock Synchronization

Of all synchronization solutions currently available for small cells, synchronization based on GPS and air interface is not applicable to small cells that are densely deployed over a wide area. Other synchronization modes, such as 1588v2 and synchronous Ethernet, are better suited to these small cells. Existing FTTx networks enable clock synchronization through 1588V2, synchronous Ethernet, and 1PPS+ToD or as defined by protocols of the PON system.

Hierarchical QoS

Small cells may be deployed in the same network where there are existing broadband and Wi-Fi users. Robust service-processing mechanism and bandwidth allocation capability are needed to guarantee services of different classes and to ensure that wireless signaling is reliable for mobile video, data, and voice. The PON FTTx system provides flexible QoS scheduling mechanisms at the port, user, and service levels to prioritize the forwarding of small-cell services and to improve user experience.

Complete Service Protection

In an FTTx network, PON provides abundant protection mechanisms, including Type B and Type C protection for OLT PON ports and redundancy for backbone fiber, branch fiber, and ONT PON ports. PON OLT uplink ports also support LACP, ring networking, and MSTP. Protection modes can be flexibly used for common hotspots, cells, or even macro cells in important areas.

Bandwidth Matching

As wireless technology advances, there is a growing demand for bandwidth. xPON is developing in line with wireless broadband access technologies from EPON/GPON to 10G PON and next-generation PON and carries GE, 10GE, and n × 10GE access bandwidth. The technology and bandwidth capabilities of PON in its different phases will meet the backhaul bandwidth needs of 3G, 4G and future 5G.

Flexible Power Supply and Intelligent OAM

Since small cells are deployed in complex environments, backhaul equipment needs to support flexible power supply and fast fault handling. The PON system can provide remote power supply for some small cells through PoE and PoE+. It also provides an end-to-end intelligent OAM system that enables easy daily OAM and quick fault location and handling.

As LTE cells can be well carried over FTTx networks, operators in many countries including the U.S., Japan, South Korea, Spain, Russia and Canada have used xPON FTTx networks to backhaul LTE macro cells and small cells. This approach has brought them considerable investment returns.

FTTM for Various Small-Cell Deployment Scenarios

There are two small-cell deployment scenarios in areas where LTE coverage and capacity is limited: indoor and outdoor. Indoor scenarios include coverage and capacity expansion for homes, offices, and high-rise buildings. Outdoor scenarios include coverage for outdoor hotspots, blind spots, traffic infrastructure, suburbs, and rural areas. ZTE has rolled out a fiber-to-the-mobile (FTTM) solution for these scenarios (Fig. 1).

In these areas, operators can flexibly use existing xPON FTTx resources to deploy small cells. A small cell can incorporate Wi-Fi, even into a home gateway unit. In addition to wireless network services, the small cell also provides new value-added services because small cells are cheap, provide good coverage, and have diverse interfaces. A small cell can also be integrated into a home gateway, enterprise gateway, or enterprise information engine to serve as a brand-new integrated service platform. In the future, small cells will be more intelligent and integrated and will support 3G, LTE and Wi-Fi. They will be further integrated into the Internet of Things, near-field communication, high-definition set-top box, video surveillance, enterprise broadcast platforms, and smart home control. Small cells will evolve to become integrated, cloud-based, social, intelligent super-cells. FTTx access networks can be smoothly evolved and have a range of ONUs that meet the needs of different bearer interfaces with small cells.

ZTE’s xPON FTTM solution provides a series of system and terminal equipment. Multiple types of ONUs are used in the solution such as integrated, low-cost ONTs with SFP modules, converged multi-port ONUs, and outdoor ONTs with high adaptability to environment. The solution unifies management through an end-to-end visual interface and satisfies the requirements of indoor and outdoor small cell scenarios. The delay, QoS, clock synchronization, and power supply requirements for LTE bearer network can also be met. Moreover, ZTE’s xPON FTTM products support smooth technological evolution to keep pace with the development of wireless broadband networks.

FTTM Accommodates LTE Growth and Ushers in a New Era for Mobile Broadband Networks