tokens: ['within', 'the', 'AL', 'To', 'properly', 'monitor', 'for', 'integrity', 'in', 'the', 'positioning', 'system', 'both', 'the', 'fault', 'and', 'faultfree', 'conditions', 'which', 'potentially', 'lead', 'to', 'MI', 'or', 'HMI', 'need', 'to', 'be', 'characterized', 'for', 'the', 'network', 'and', 'the', 'UE', 'Figure', 'A', 'illustrates', 'the', 'concept', 'of', 'MI', 'and', 'HMI', 'with', 'respect', 'to', 'the', 'KPIs', 'PL', 'and', 'PE', 'Figure', 'A', 'Relationship', 'between', 'Positioning', 'Error', 'PE', 'Protection', 'Level', 'PL', 'Alert', 'Limit', 'AL', 'MI', 'and', 'HMI', '', 'A', 'useful', 'representation', 'for', 'interpreting', 'the', 'relationship', 'between', 'the', 'positioning', 'integrity', 'KPIs', 'and', 'PL', 'is', 'the', 'socalled', 'Stanford', 'Diagram', '', 'in', 'Figure', 'B', 'It', 'should', 'be', 'noted', 'that', 'the', 'Positioning', 'Error', 'PE', 'in', 'this', 'diagram', 'is', 'the', 'difference', 'between', 'the', 'true', 'position', 'and', 'the', 'estimated', 'position', 'computed', 'by', 'the', 'positioning', 'device', 'In', 'practice', 'the', 'true', 'position', 'is', 'not', 'known', 'Figure', 'B', 'Stanford', 'Diagram', 'for', 'integrity', 'events', 'adapted', 'from', '', 'Important', 'observations', 'can', 'be', 'made', 'from', 'Figure', 'B', 'in', 'the', 'context', 'of', 'this', 'study', '', 'The', 'conditions', 'represented']