Switchable Ad Hoc and Wide Area Network Coverage
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Solution Overview
Problem
Conventional cellular systems face challenges in providing guaranteed localized coverage within neighborhoods due to high costs and impracticality of installing base stations for indoor and outdoor locations, leading to reduced capacity and increased costs for users, with traditional systems struggling to effectively manage transitions between wide area and localized network coverage.
Innovation Solution
The system enables mobile subscriber units to switch between wide area and ad hoc network coverage using dual network communication capabilities, with a last hop node defining the neighborhood cell and facilitating communication through ad hoc routing, minimizing the need for costly infrastructure and backhaul, and allowing seamless handovers between network modes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If base stations are installed for all indoor and outdoor locations within a service area to guarantee localized coverage, then coverage reliability is improved, but system cost increases significantly
Solution Approach 1:
Subscriber units within the neighborhood cell serve themselves by directly communicating with each other via ad hoc routing, eliminating the need for traditional base stations to provide localized coverage. The system self-organizes peer-to-peer connections among subscribers, with only a single gateway node requiring backhaul connection to the wide area network.
Solution Approach 2:
The patent extracts the base station function from the localized neighborhood coverage provision, separating it from the traditional cellular architecture. Base stations are removed from indoor and most outdoor locations, with coverage provided instead by subscriber units themselves through ad hoc networking, requiring infrastructure only at the gateway node.
2Productivity
If microcells or picocells are deployed to provide localized coverage, then coverage capacity is improved, but the capacity of reserved cells is reduced due to co-channel interference
Solution Approach 1:
The patent segments the cellular coverage into two distinct parts: wide area network coverage using traditional base stations, and localized neighborhood coverage using ad hoc peer-to-peer connections between subscriber units. This segmentation eliminates co-channel interference between microcells and macrocells, as they operate independently without shared frequencies in the neighborhood area.
Solution Approach 2:
The gateway node acts as an intermediary between the ad hoc neighborhood network and the wide area network. It provides the single backhaul connection point, allowing neighborhood calls to be routed through the gateway to the WAN without requiring multiple backhaul connections or frequency coordination with adjacent macrocells.
3Object-affected harmful factors
If different carrier frequencies are used for microcells to prevent non-subscriber access, then network security is improved, but implementation cost increases due to backhaul requirements
Solution Approach 1:
Subscriber units authenticate and establish direct ad hoc connections with each other within the neighborhood cell, serving their own communication needs without requiring traditional base station infrastructure or frequency-based access control. The ad hoc protocol inherently manages subscriber access through direct peer-to-peer authentication and connection establishment.
Solution Approach 2:
The patent removes the need for frequency-based access control and multiple backhaul connections by extracting the localized coverage function from traditional base stations. A single gateway node provides the necessary backhaul connection, while subscriber units handle their own access control through ad hoc networking protocols.
4Adaptability or versatility
If neighborhood service is tiered with different costs for local and outside service, then service differentiation is improved, but traditional cellular systems cannot effectively control transitions between coverage areas
Solution Approach 1:
The patent implements dynamic transition control where subscriber units automatically switch between wide area network and ad hoc neighborhood network modes based on their location and service needs. The system dynamically routes calls through the gateway when in neighborhood mode, enabling cost-based service differentiation without manual intervention or complex handoff protocols.
Solution Approach 2:
The system uses feedback from the subscriber unit's location and network mode to automatically adjust routing and billing. When a subscriber unit detects it is within the neighborhood cell, the system feedbacks routing information through the gateway for localized calls, enabling automatic service tiering and cost differentiation based on call origin and destination.
Data Source
AI summary
A method of communicating in and around a localized wireless coverage area according to the present invention provides cellular coverage to a neighborhood cell (18) in which service might otherwise not be possible or in which a high percentage of calls would otherwise end up being dropped. Specifically, a neighborhood cell (18) is defined by either one or more fixed last hop nodes (20) or mobile last hop nodes (120). If a source mobile subscriber unit (12) communicates with a destination unit through wide area wireless network coverage, the source mobile subscriber unit (12) is handed over to ad hoc wireless network coverage either automatically or upon the occurrence of a high frame error rate when it enters the neighborhood cell (18) to maintain communication with the destination unit. If the source mobile subscriber unit (12) is already communicating through ad hoc wireless coverage within the neighborhood cell (18), it is handed over to wide area wireless network coverage when it exits the neighborhood cell (18) to maintain communication with the destination unit.